FIELD OF THE INVENTION 
     The invention pertains to the field of two way mailing envelopes. More particularly, the invention pertains to two way mailing envelopes that include a fold out second mailing flap that provides the proper return information for mailing while the first mailing information is no longer shown on the outside of the envelope. 
     BACKGROUND OF THE INVENTION 
     Over the years many remailable or two way envelopes have been designed. However, the majority of the businesses with a need for receiving return mail still provide separate return envelopes for their customers. 
     There is a greater awareness concerning the conservation of resources and reduction of waste such that many companies are voluntarily making efforts to reduce waste and use resources more efficiently. Therefore, the lack of more wide spread use of two way envelopes is surprising and most likely related to the increased cost and difficulty of use of previously designed two way envelope. 
     Prior envelopes with second mailing flaps are often difficult to use or can not be used with standard postal equipment (e.g. bar code readers) or office equipment (e.g.) letter openers. 
     U.S. Pat. No. 3,096,925 teaches a two way envelope that is sealed for a first mailing by a removable tab on an extension from the back of the envelope. Once the tab is removed the extension from the back can be brought further down the front by folding the front and back of the envelope at a lower line across the top. This envelope has many disadvantages. The envelope would be rendered useless if a standard letter opener were used. The user must place the initial address high up near the top of the envelope so that it is covered during the second mailing. This is contrary to standard practice and would be not be usable with bar code scanning techniques. 
     U.S. Pat. No. 4,308,987 teaches a two way envelope that includes a second mailing panel that is attached to the back of the envelope and stuffed inside the envelope during the first mailing. After the first mailing, the second mailing flap is removed and folded over the first mailing information. The sides of the second mailing flap are contoured to allow removal. Even so, the second mailing flap of this type of envelope is extremely difficult to remove without damage. The flap does not cover the entire front of the envelope. Depending upon how the first user positions the return address, some portion of it may show on the outside of the envelope during the second mailing. U.S. Pat. No. 4,332,346 is similar to the envelope taught in U.S. Pat. No. 4,308,987, however, it also teaches providing a spot of glue to prevent the return flap from rising up prematurely and being cut by a letter opener. The glue makes the second mailing flap even more difficult to remove. 
     U.S. Pat. Nos. 4,565,317, 4,595,138, 4,730,768, 5,197,663 and 5,224,647 all two way envelopes that include a second mailing panel that is attached to the back of the envelope and stuffed inside the envelope during the first mailing. After the first mailing, the second mailing flap is removed and folded over the first mailing information. In some embodiment the sides of the second mailing flap are contoured to allow removal, in others the flap is folded. Even so, the second mailing flap of this type of envelope is extremely difficult to remove without damage. All of these designs are deficient in that they do not provide a second mailing flap that is extremely easy to fold out and secure. 
     SUMMARY OF THE INVENTION 
     Therefore, it is the primary object of the present invention to provide envelopes that include a second mailing flap that is easy to fold out and secure to prepare the envelope for a second mailing. 
     The present invention includes a two way envelope that has a front panel, a rear panel, side flaps and a first mailing flap that seals the envelope during the first mailing like any other normal envelope. In addition to these standard features, the envelopes of the present invention include a second mailing flap which folds out to cover a portion of the first mailing information and display second mailing information. The second mailing flap can seal the envelope for the second mailing or a second mailing sealing flap can be provided. 
     The two way envelope differs from the previous two envelopes primarily in the ease with which the second mailing flap is folded out. The sides of the envelope are closed from the bottom of the envelope to only a portion of the way to the top. The fact that the top portion of the sides are not glued allows the front and rear panels to be spread apart and the second mailing flap can be removed from inside the envelope or the first mailing flap can be inserted with ease. 
     The present invention also includes envelopes that have a second mailing flap or a second sealing flap folded on the outside of the envelope and covered by the first mailing flap during the first mailing. Once the envelope is opened, the second mailing flap or second sealing flap are extremely easy to unfold. In some embodiments, the first mailing information is provided on what would normally look like the rear of the envelope. 
     Further objects and advantages will be seen from the following detailed description taken in conjunction with the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIGS. 1a and 1b show the inside and outside of Example 1 of a two way envelope that has a second mailing flap folded inside the envelope during the first mailing. 
     FIGS. 2a, 2b and 2c show different options for providing the return and forward addressers during the first mailing. 
     FIG. 3 shows a cut away view of a two way envelope that has a second mailing flap folded inside the envelope during the first mailing and folds out to cover the entire front panel of the envelope. 
     FIG. 4 shows the front of a two way envelope that has a second mailing flap folded out and covering the entire front panel of the envelope for the second mailing. 
     FIG. 5 is a cross sectional view through FIG. 3 that shows the second mailing flap folded up during the first mailing. 
     FIG. 6 is a cross sectional view through FIG. 4 that shows the second mailing flap folded out during the second mailing. 
     FIGS. 7a and 7b show the inside and outside of Example 2 of a two way envelope that has a second mailing flap folded inside the envelope during the first mailing. 
     FIG. 8 shows a cut away view of a two way envelope that has a second mailing flap folded inside the envelope during the first mailing and folds out to cover the return addresser on the front panel of the envelope. 
     FIG. 9 shows the front of a two way envelope that has a second mailing flap folded out and covering the return addresser on the front panel of the envelope for the second mailing. 
     FIG. 10 is a cross sectional view through FIG. 8 that shows the second mailing flap folded up during the first mailing. 
     FIG. 11 is a cross sectional view through FIG. 9 that shows the second mailing flap folded out during the second mailing. 
     FIGS. 12a and 12b show the inside and outside of Example 3 of a two way envelope that has a second mailing flap folded inside the envelope during the first mailing. 
     FIGS. 13a and 13b show cut away views of a two way envelope that has a first mailing flap that includes a tear strip and a notch respectively. 
     FIG. 14 is a cross sectional view that shows the second mailing flap of folded up during the first mailing. 
     FIG. 15 is a cross sectional view that shows the second mailing flap folded out during the second mailing. 
     FIGS. 16a and 16b show the inside and outside of Example 4 of a two way envelope that has a second mailing flap folded inside the envelope during the first mailing. 
     FIG. 17 is a cross sectional view that shows the second mailing flap of folded up during the first mailing. 
     FIG. 18 is a cross sectional view that shows the second mailing flap folded out during the second mailing. 
     FIGS. 19a and 19b show the inside and outside of Example 5 of a two way envelope that has a second mailing flap folded inside the envelope during the first mailing. 
     FIG. 20 shows a rear view of a two way envelope that has a first mailing flap that includes a perforation string. 
     FIGS. 21a and 21b show the inside and outside of Example 6 of a two way envelope that has a second mailing flap folded inside the envelope during the first mailing. 
     FIGS. 22a and 22b show the inside and outside of Example 7 of a two way envelope that has a second mailing flap folded outside the envelope and under the first mailing flap during the first mailing. 
     FIG. 23 is a cut away view of the two way envelope showing the second mailing flap on the outside of the envelope and folded inward toward the envelope. 
     FIG. 24 is a cross sectional view that shows the second mailing flap folded up during the first mailing. 
     FIGS. 25a and 25b show the inside and outside of Example 8 of a two way envelope that has a second mailing flap folded outside the envelope and under the first mailing flap during the first mailing. 
     FIG. 26 is a cut away view of the two way envelope showing the second mailing flap on the outside of the envelope and folded outward away from the envelope. 
     FIG. 27 is a cross sectional view that shows the second mailing flap folded up during the first mailing. 
     FIGS. 28a and 28b show the inside and outside of Example 9 of a two way envelope that has a second mailing flap folded outside the envelope and under the first mailing flap during the first mailing. 
     FIG. 29 is a cross sectional view that shows the second mailing flap folded up during the first mailing. 
     FIGS. 30a and 30b show the inside and outside of Example 10 of a two way envelope that has a second mailing flap folded outside the envelope and under the first mailing flap during the first mailing. 
     FIG. 31 is a cross sectional view that shows the second mailing flap folded up during the first mailing. 
     FIGS. 32a and 32b show the inside and outside of Example 11 of a two way envelope that has a second mailing flap folded outside the envelope and under the first mailing flap during the first mailing. 
     FIG. 33 is a cut away view of the two way envelope showing the second mailing flap on the outside of the envelope and folded inward toward the envelope. 
     FIGS. 34a and 34b show the inside and outside of Example 12 of a two way envelope that has a second mailing flap folded outside the envelope and under the first mailing flap during the first mailing. 
     FIG. 35 is a cut away view of the two way envelope showing the second mailing flap on the outside of the envelope and folded outward away from the envelope. 
     FIGS. 36a and 36b show the inside and outside of Example 13 of a two way envelope that has a second mailing flap folded outside the envelope on the front side of the envelope. 
     FIG. 37 is a front view of the two way envelope showing the first mailing return addresser on the front of the first mailing flap. 
     FIG. 38 is a cut away view of the two way envelope showing the second mailing flap on the outside of the envelope and folded outward away from the envelope. 
     FIG. 39 is a cross sectional view through the envelope shown in FIG. 38 that shows the second mailing flap folded up during the first mailing. 
     FIG. 40 is front view of the two way envelope with the second mailing flap folded out for the second mailing. 
     FIG. 41 is a cross sectional view through the envelope shown in FIG. 40 that shows the second mailing flap folded out for the second mailing. 
     FIGS. 42a and 42b show the inside and outside of Example 14 of a two way envelope that has a second mailing flap folded outside the envelope on the front side of the envelope. 
     FIG. 43 is a cut away view of the two way envelope showing the second mailing flap on the outside of the envelope and folded inward toward the envelope. 
     FIG. 44 is a cross sectional view through the envelope shown in FIG. 43 that shows the second mailing flap folded up during the first mailing. 
     FIGS. 45a and 45b show the inside and outside of Example 15 of a two way envelope that has a second mailing flap folded outside the envelope on the front side of the envelope. 
     FIGS. 46a and 46b are front views of the two way envelope showing the first mailing return addresser on the front of the first mailing flap. 
     FIG. 47 is a cut away view of the two way envelope showing the second mailing flap on the outside of the envelope and folded outward away from the envelope. 
     FIG. 48 is a cross sectional view through the envelope shown in FIG. 47 that shows the second mailing flap folded up during the first mailing. 
     FIG. 49 is front view of the two way envelope with the second mailing flap folded out for the second mailing. 
     FIG. 50 is a cross sectional view through the envelope shown in FIG. 49 that shows the second mailing flap folded out for the second mailing. 
     FIGS. 51a and 51b show the inside and outside of Example 16 of a two way envelope that has a second mailing flap folded outside the envelope on the front side of the envelope. 
     FIG. 52 is a cut away view of the two way envelope showing the second mailing flap on the outside of the envelope and folded outward away from the envelope. 
     FIG. 53 is a cross sectional view through the envelope shown in FIG. 52 that shows the second mailing flap folded up during the first mailing. 
     FIGS. 54a and 54b show the inside and outside of Example 17 of a two way envelope that has a second mailing flap folded outside the envelope on the front side of the envelope. 
     FIG. 55 is a front view of the two way envelope showing the first mailing return addresser on the front of the first mailing flap and a pressure sensitive sealing strip on the bottom of the front panel. 
     FIG. 56 is a cut away view of the two way envelope showing the second mailing flap on the outside of the envelope and folded inward toward the envelope. 
     FIG. 57 is front view of the two way envelope with the second mailing flap folded out and the first mailing flap folded down for the second mailing. 
     FIG. 58 is a cross sectional view through the envelope shown in FIG. 57 that shows the second mailing flap folded out and the first mailing flap folded down for the second mailing. 
     FIGS. 59a and 59b show the inside and outside of Example 18 of a two way envelope that has a second mailing flap folded outside the envelope on the front side of the envelope. 
     FIG. 60 is a cut away view of the two way envelope showing the second mailing flap on the outside of the envelope and folded outward away from the envelope and a pressure sensitive sealing strip on the front panel. 
     FIGS. 61a and 61b show the inside and outside of Example 19 of a two way envelope that has a second mailing flap folded outside the envelope on the front side of the envelope. 
     FIGS. 62a and 62b are front views of the two way envelope showing the first mailing return addresser on the front of the first mailing flap and a perforation and string or a tear strip for opening the envelope. 
     FIGS. 63a and 63b show the inside and outside of Example 20 of a two way envelope that has a second mailing flap folded outside the envelope on the front side of the envelope. 
     FIGS. 64a and 64b show the inside and outside of Example 21 of a two way envelope that has a second mailing flap that is integrated with the front panel. 
     FIG. 65 is a cross sectional view through the envelope shown in FIGS. 64a and 64b that shows the sealed envelope during the first mailing. 
     FIG. 66 is front view of the two way envelope that has been sealed for the second mailing. 
     FIG. 67 is a cross sectional view through the envelope shown in FIG. 66 that shows the envelope sealed for the second mailing. 
     FIGS. 68a and 68b show the inside and outside of Example 22 of a two way envelope that has a second mailing flap that is integrated with the front panel and folds inside the envelope. 
     FIG. 69 is a cut away view of the two way envelope showing the second mailing flap on the inside of the envelope and folded inward toward the envelope. 
     FIG. 70 is a cross sectional view through the envelope shown in FIG. 69 that shows the sealed envelope during the first mailing. 
     FIGS. 71a and 71b show the inside and outside of Example 23 of a two way envelope that has a second mailing flap that is integrated with the front panel and folds inside the envelope. 
     FIG. 72 is a cross sectional view through the envelope shown in FIGS. 71a and 71b that shows the sealed envelope during the first mailing. 
     FIGS. 73a and 73b show the inside and outside of Example 24 of a two way envelope that has a second mailing flap that is integrated with the front panel. 
     FIG. 74 is a cut away view of the two way envelope showing the first mailing flap folded toward the envelope and sealed. 
     FIG. 75 is a cross sectional view through the envelope shown in FIG. 74 that shows the sealed envelope during the first mailing. 
     FIG. 76 is front view of the two way envelope that has been sealed for the second mailing. 
     FIG. 77 is a cross sectional view through the envelope shown in FIG. 76 that shows the envelope sealed for the second mailing. 
     FIGS. 78a and 78b show the inside and outside of Example 25 of a two way envelope that has a second mailing flap that is integrated with the front panel. 
     FIG. 79 is a cut away view of the two way envelope showing the second mailing flap folded inside the envelope and the first mailing flap folded toward the envelope and sealed. 
     FIG. 80 is a cross sectional view through the envelope shown in FIG. 79 that shows the sealed envelope during the first mailing. 
     FIGS. 81a and 81b show the inside and outside of Example 26 of a two way envelope that has a second mailing flap that is integrated with the front panel. 
     FIG. 82 is a cross sectional view through the envelope shown in FIGS. 81a and 81b that shows the sealed envelope during the first mailing. 
     FIGS. 83a and 83b show the inside and outside of Example 27 of a two way envelope that has a second mailing flap that is integrated with the front panel and the first mailing flap includes a perforation and a string. 
     FIGS. 84a and 84b show the inside and outside of Example 28 of a two way envelope that has a second mailing flap that is integrated with the front panel and the first mailing flap includes a perforation and a string. 
     FIGS. 85a and 85b show the inside and outside of Example 29 of a two way envelope that has a second mailing flap that is integrated with the front panel and the first mailing flap includes a perforation and a string. 
     FIGS. 86a and 86b show the inside and outside of Example 30 of a two way envelope that has a second mailing flap that is integrated with the first mailing flap. 
     FIG. 87 is a cut away view of the two way envelope showing the second mailing flap folded outside the envelope away from the envelope. 
     FIG. 88 is a cross sectional view through the envelope shown in FIG. 87 that shows the sealed envelope during the first mailing. 
     FIG. 89 is front view of the two way envelope that has been sealed for the second mailing. 
     FIG. 90 is a cross sectional view through the envelope shown in FIG. 89 that shows the envelope sealed for the second mailing. 
     FIGS. 91a and 91b show the inside and outside of Example 31 of a two way envelope that has a second mailing flap that is integrated with the first mailing flap. 
     FIG. 92 is a cut away view of the two way envelope showing the second mailing flap folded outside the envelope toward the envelope. 
     FIG. 93 is a cross sectional view through the envelope shown in FIG. 92 that shows the sealed envelope during the first mailing. 
     FIGS. 94a and 94b show the inside and outside of Example 32 of a two way envelope that has a second mailing flap that is integrated with the first mailing flap. 
     FIG. 95 is a cut away view of the two way envelope showing the second mailing flap folded outside the envelope away from the envelope. 
     FIG. 96 is a cross sectional view through the envelope shown in FIG. 95 that shows the sealed envelope during the first mailing. 
     FIG. 97 is front view of the two way envelope that has been sealed for the second mailing. 
     FIG. 98 is a cross sectional view through the envelope shown in FIG. 97 that shows the envelope sealed for the second mailing. 
     FIGS. 99a and 99b show the inside and outside of Example 33 of a two way envelope that has a second mailing flap that is integrated with the first mailing flap. 
     FIG. 100 is a cross sectional view through the envelope shown in FIGS. 99a and 99b that shows the sealed envelope during the first mailing. 
     FIGS. 101a and 101b show the inside and outside of Example 34 of a two way envelope that has a second mailing flap that is integrated with the first mailing flap. 
     FIG. 102 is a cut away view of the two way envelope showing the second mailing flap folded outside the envelope away from the envelope. 
     FIG. 103 is a cross sectional view through the envelope shown in FIG. 102 that shows the sealed envelope during the first mailing. 
     FIG. 104 is front view of the two way envelope that has been sealed for the second mailing. 
     FIG. 105 is a cross sectional view through the envelope shown in FIG. 104 that shows the envelope sealed for the second mailing. 
     FIGS. 106a and 106b show the inside and outside of Example 35 of a two way envelope that has a second mailing flap that is integrated with the first mailing flap. 
     FIG. 107 is a cut away view of the two way envelope showing the second mailing flap folded outside the envelope away from the envelope and the front panel folded inside the envelope. 
     FIG. 108 is a cross sectional view through the envelope shown in FIG. 107 that shows the sealed envelope during the first mailing. 
     FIGS. 109a and 109b show the inside and outside of Example 36 of a two way envelope that has a second mailing flap that is integrated with the first mailing flap. 
     FIG. 110 is a cut away view of the two way envelope showing the second mailing flap folded outside the envelope away from the envelope and the front panel folded inside the envelope. 
     FIG. 111 is a cross sectional view through the envelope shown in FIG. 110 that shows the sealed envelope during the first mailing. 
     FIG. 112 is front view of the two way envelope that has been sealed for the second mailing. 
     FIG. 113 is a cross sectional view through the envelope shown in FIG. 112 that shows the envelope sealed for the second mailing. 
     FIGS. 114a and 114b show the inside and outside of Example 37 of a two way envelope that has a second mailing flap that is integrated with the first mailing flap and a second sealing flap attached to the front panel. 
     FIG. 115 is a cut away view of the two way envelope showing the second mailing flap folded outside the envelope away from the envelope and the second sealing flap folded outside the envelope away from the envelope. 
     FIG. 116 is a cross sectional view through the envelope shown in FIG. 115 that shows the sealed envelope during the first mailing. 
     FIGS. 117a and 117b show the inside and outside of Example 38 of a two way envelope that has a second mailing flap that is integrated with the first mailing flap and a second sealing flap attached to the front panel. 
     FIG. 118 is a cut away view of the two way envelope showing the second mailing flap folded outside the envelope away from the envelope and the second sealing flap folded outside the envelope toward the envelope. 
     FIG. 119 is a cross sectional view through the envelope shown in FIG. 118 that shows the sealed envelope during the first mailing. 
     FIGS. 120a and 120b show the inside and outside of Example 39 of a two way envelope that has a second mailing flap that is integrated with the first mailing flap and a second sealing flap attached to the front panel. 
     FIG. 121 is a cut away view of the two way envelope showing the second sealing flap folded inside the envelope. 
     FIG. 122 is a cross sectional view through the envelope shown in FIG. 121 that shows the sealed envelope during the first mailing. 
     FIG. 123 is a cross sectional view through the envelope shown in FIGS. 120a and 120b that shows the envelope sealed for the second mailing. 
     FIGS. 124a and 124b show the inside and outside of Example 40 of a two way envelope that has a second mailing flap that is integrated with the first mailing flap and a second sealing flap attached to the second mailing flap. 
     FIG. 125 is a cut away view of the two way envelope showing the second mailing flap and the second sealing flap folded inside the envelope toward the envelope. 
     FIG. 126 is a cross sectional view through the envelope shown in FIG. 125 that shows the sealed envelope during the first mailing. 
     FIG. 127 is a cross sectional view through the envelope shown in FIGS. 124a and 124b that shows the envelope sealed for the second mailing. 
     FIGS. 128a and 128b show the inside and outside of Example 41 of a two way envelope that has a second mailing flap that is integrated with the first mailing flap and is attached to a second sealing flap. 
     FIG. 129 is a cut away view of the two way envelope showing the second mailing flap and the second sealing flap folded inside the envelope away from the envelope. 
     FIG. 130 is a cross sectional view through the envelope shown in FIG. 129 that shows the sealed envelope during the first mailing. 
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     This detailed descriptions provides forty one different examples of two way envelopes. In general, all of the envelopes can be constructed from a single sheet of paper and figures depicting the inside and outside of each envelope prior to folding are included. In addition, a front view of the sealed envelope during first and second mailings is provided. To provide a better understanding of how the envelope is folded and used a cut away view for each example and cross sectional representations of the sealed envelope during first and second mailings are shown. The examples are similar and therefore, some of the views of the examples look very similar. To avoid duplication of figures, the description refers to views of previously described examples. For clarity, the following table has been provided which lists the figure that shows each view for a particular example. 
     
         __________________________________________________________________________ Inside &amp;      1st mail    1st mail                       2nd mail                             2nd mailExample Outside      Front view            Cutaway                  X-section                       Front view                             X-section__________________________________________________________________________ 1     1a-b       2a-c  3     5    4     6 2     7a-b       2a-c  8    10    9    11 3    12a-b       2a-c  13a-b                  14    4    15 4    16a-b       2a-c  13a-b                  17    9    18 5    19a-b       2a-c  20   .sup.  5.sup.1                        4    15 6    21a-b       2a-c  20   .sup. 10.sup.1                        9    18 7    22a-b       2a-c  23   24    9    11 8    25a-b       2a-c  26   27    9    11 9    28a-b       2a-c  23   29    9    1810    30a-b       2a-c  26   31    9    1811    32a-b       2a-c  33   .sup. 24.sup.1                        9    1812    34a-b       2a-c  35   .sup. 27.sup.1                        9    1813    36a-b      37     38   39   40    4114    42a-b      37      43  44   40    4115    45a-b      37, 46a-b             47   48   49    5016    51a-b      37, 46a-b             52   53   49    5017    54a-b      55     56   .sup. 53.sup.2                       57    5818    59a-b      55     60   .sup. 48.sup.2                       57    5819    61a-b      62a-b  38   .sup. 39.sup.1                       49    5020    63a-b      62a-b  43   .sup. 44.sup.1                       49    5021    64a-b      37          65   66    6722    68a-b      37     69   70   66    6723    71a-b      37     69   72   40    4124    73a-b      37, 46a-b             74   75   76    7725    78a-b      37, 46a-b             79   80   76    7726    81a-b      37, 46a-b             79   82   49    5027    83a-b      62a-b       .sup. 65.sup.1                       76    7728    84a-b      62a-b       .sup. 70.sup.1                       76    7729    85a-b      62a-b       .sup. 72.sup.1                       49    5030    86a-b      37, 46a-b             87   88   89    9031    91a-b      37, 46a-b             92   93   89    9032    94a-b      37, 46a-b             95   96   97    9833    99a-b      37, 46a-b             92   100  97    9834    101a-b      37    102   103  104   10535    106a-b      37    107   108  104   10536    109a-b      37    110   111  112   11337    114a-b      37    115   116  112   11338    117a-b      37    118   119  112   11339    120a-b      55    121   122  112   12340    124a-b      55    125   126   4    12741    128a-b      55    129   130   4    127__________________________________________________________________________ .sup.1 The view looks the same as the listed figure except that the first mailing flap is a little longer to accommodate a perforation and a string .sup.2 The view looks the same as the listed figure except that a pressur sensitive glue strip is included on the front panel. 
    
    
    
     EXAMPLE 1 
     FIGS. 1a through 6 show Example 1 of a two way envelope that has a second mailing flap 5 folded inside the envelope during the first mailing and folds out to cover the entire front panel of the envelope during the second mailing. Referring now to FIGS. 1a and 1b, the inside and outside of a two way envelope are shown respectively. The envelope has a front panel 1, a rear panel 2, and two side extension flaps 3. The envelope is sealed for the first mailing by a first mailing flap 4. A second mailing flap extends from the rear panel 2 of the envelope. In general, the envelopes of the present invention can be made from a single sheet of paper that is folded along the fold lines 6 shown in the figures. 
     In general, the parts of the two-way envelopes described herein are defined by their respective function rather than their structural location. Therefore it is important to refer to the Figures in conjunction with the description to understand the construction and operation of the two-way envelopes. 
     The definitions of &#34;front&#34; and &#34;rear&#34; can be a bit confusing with a two-way envelope. Therefore, the &#34;front&#34; of the envelope is always described as the face of the envelope that has the forward addresser during the first mailing. The &#34;rear&#34; of the envelope is merely opposite the &#34;front&#34;. The term &#34;first mailing flap&#34; as used herein defines the part of the envelope that is used to seal the envelope during the first mailing. The &#34;second mailing flap&#34; as used herein always refers to a part of the envelope that has second mailing information on it. Therefore, the removable glue spots used to seal the envelope are labeled with reference numeral 26 and the removeable glue spots used to help keep a flap folded are labled with reference numeral 25. 
     The first mailing return addresser 10 can be provided by a window as shown in FIG. 2a or printed on the envelope as shown in FIGS. 2b and 2c. Likewise the first mailing forwarding addresser 11 can be provided by a window as shown in FIGS. 2a and 2b or printed on the envelope as shown in FIG. 2c. As shown in FIG. 2b the two may be combined as the purchaser desires. The windows can have a clear plastic covering or merely be holes in the paper. 
     The second mailing return addresser 20 and the second mailing forward addresser 21 are shown in FIG. 4 as being preprinted on the second mailing flap 5. The second mailing flap 5 extends from the rear panel with its edge long enough to cover the whole front panel and is folded three times underneath the rear panel during the first mailing as shown in FIGS. 3 and 5. 
     The side extension flaps 3 are both attached to the front panel. The top edge of the side flaps 3 are cut at an angle to facilitate easy insertion of mail. This taper could be in any desired shape the proper length and degree of the taper will be determined by particular machinery used to stuff envelopes. The side flaps 3 are adhered to the inner face of the rear panel with an unadhered portion at the top. The unadhered portion is a sufficient distance down the side of the envelope to be at least be below the folded second mailing flap 5 as shown in FIG. 3. 
     The unadhered portion of the side flaps 3 is a very important part of the present invention. It allows the second mailing flap 5 to be removed and the first mailing flap 4 to be stored easily. As can be seen in FIG. 4 the second mailing flap 5 is the full length of the envelope. This would not be possible with prior art envelopes, because they seal the entire side of the envelope. They are forced to provide a narrower second mailing flap. The fact that the second mailing flap 5 can cover the entire front of the envelope will allow the envelope of the present invention to be used in countries like Canada that require that the forwarding and return information not be on the sealing side of the envelope because once the second mailing flap 5 is adhered, both side of the envelope will be smooth and easy to read. If the length of the envelope was extended, the side flaps 3 could be deleted and the front and back panels 1 and 2 could be adhered directly to one another leaving the same unadhered portion as described above. 
     Any type of glue or adhesive may be used to adhere the side flaps 3. The forward flap 4 could include removable glue in spots 26, as shown in FIG. 1a, or in lines on the inner face of the flap 4. The removable glue would allow the envelope to be opened after the first mailing without causing significant damage to the envelope. However, regular adhesives could also be used if the sender anticipated that the receiver would be using a letter opener. The use of a letter opener would not hurt the second mailing flap 5. In fact the forward mailing flap 4 could include a perforation to allow the first mailing flap 4 to be removed after the first mailing. 
     As mentioned above, the second mailing flap 5 is folded three times along the fold lines 6 during the first mailing. However, once folded out and over the front of the envelope a fold line 28, or a perforation, allows the second mailing flap to fold easily over the front panel 1. The height of the envelope will increase very slightly when the second mailing flap 5 is folded over. The glue or adhesive is on the inner face of the flap. 
     To assist in holding the second mailing flap 5 during the first mailing, removable glue spots 25 could be added. The glue would pop loose when the second mailing flap 5 was folded out. The glue along the bottom edge and side of the second mailing flap 5 for sealing the envelope during the second mailing could be any appropriate adhesive, e.g. moisture sensitive glue. 
     EXAMPLE 2 
     FIGS. 7a through 11 show Example 2 of a two way envelope that is very similar to the envelope shown in FIGS. 1a through 6, except that the second mailing flap 5 only covers the return addresser 10 and postage area for the first mailing on the front panel 1. FIGS. 7a and 7b show the inside and outside of the two way envelope. FIG. 8 shows the back of the envelope with the second mailing flap 5 folded twice inside the envelope during the first mailing. FIG. 9 shows the front of the envelope after the second mailing flap 5 has been folded out. 
     FIG. 10 is a cross sectional view through FIG. 8 that shows the second mailing flap folded up during the first mailing. FIG. 11 is a cross sectional view through FIG. 9 that shows the second mailing flap folded out during the second mailing. 
     In general, bar code information can be provided for the forward addressers 11 and 21 by either providing a bar code that shows through the window or is preprinted on the envelope, label, or second mailing flap 5. If the second mailing flap 5 does not cover the first mailing forward addresser 11 as shown in FIG. 9, then a window or label is preferable as a forward addresser 21 to provide the bar code information. 
     The envelopes shown in FIGS. 12a through 21b are similar to the envelopes shown in FIGS. 1 through 11. The second mailing flap 5 folds into the inside of the envelope and there is an unadhered portion in the sides of the envelopes to allow easy removal. The envelopes differ in the way the envelope is opened after the first mailing and in the length of the second mailing flap 5. 
     EXAMPLE 3 
     FIGS. 12a and 12b show the inside and outside of Example 3 of a two way envelope that has a second mailing flap folded inside the envelope during the first mailing and folds out to cover the entire front panel of the envelope. The first mailing flap 4 includes a fold 6 inward towards the rear panel 2. This fold could alternatively be provided by a fold and perforation. A few spots of glue 25 can be provided to keep the fold tight if desired. After the first mailing the envelope can be opened by separating the first mailing flap 4 along the fold. 
     FIG. 14 is a cross sectional view, similar to FIG. 5, that shows the second mailing flap folded up during the first mailing. The front and back of the envelope during first mailing would look the same as FIGS. 2a-2c and FIG. 3 respectively. FIG. 15 is a cross sectional view that shows the second mailing flap folded out during the second mailing, similar to FIG. 6. The second mail front looks the same as the envelope shown in FIG. 4. 
     EXAMPLE 4 
     FIGS. 16a and 16b show the inside and outside of Example 4 of a two way envelope, similar to the envelope shown in FIGS. 12a and 12b, except that the second mailing only covers the return addresser and the postage area on the front panel of the envelope. The front and back of the envelope during first mailing would look the same as FIGS. 2a-2c and FIG. 8 respectively. FIG. 17 is a cross sectional view that shows the second mailing flap of folded up during the first mailing, similar to FIG. 10. FIG. 18 is a cross sectional view that shows the second mailing flap folded out during the second mailing, similar to FIG. 11. The second mail front looks the same as the envelope shown in FIG. 9. 
     To facilitate opening a tear strip 31 can be provided in the folded first mailing flap 4, as shown in FIG. 13a. This strip 31 would be cut between two parallel perforations with an end tag to hold onto. Preferably, one of the perforations would be on the fold line 6 between the two levels of the flap 4. As another way of opening the envelope, notches 32 could be provided in each of the lower corners of the top level of the folded first mailing flap 4. 
     A perforation or a perforation and a string can be added on the fold between the front panel 1 and the first mailing flap 4 to allow the flap 4 to be removed after the first mailing. 
     EXAMPLES 5 AND 6 
     FIGS. 19a, 19b, 21a and 21b show the inside and outside of Examples 5 and 6 of two way envelopes similar to the envelopes shown in FIGS. 1a, 1b, 7a and 7b respectively except that a perforation and a string 33 is provided for opening the envelope after the first mailing and the application of glue is different. The perforation and string 33 could alternatively be provided by a peforation and a paper strip. FIG. 20 shows the back of a two way envelope that has a first mailing flap that includes a perforation and a string 33. 
     The front and cross sections of the envelope shown if FIGS. 19a and 19b looks the same as the envelopes shown in FIGS. 2a-c, FIG. 5 and FIG. 15, except that during the first mailing the first mailing flap 4 would be a little longer to accommodate the perforation and string. The second mail front looks the same as the envelope shown in FIG. 4. 
     The front and cross sections of the envelope shown in FIGS. 21a and 21b looks the same as the envelopes shown in FIGS. 2a-c, FIG. 10 and FIG. 18, except that during the first mailing the first mailing flap 4 would be a little longer to accommodate the perforation and string. The second mail front looks the same as the envelope shown in FIG. 9. 
     EXAMPLES 7-12 
     The two way envelopes shown in FIGS. 22a-35 are similar to the previous Examples, however, the second mailing flap 5 folds on the outside of the envelope rather than on the inside. In all examples, the first mailing flap 4 covers the second mailing flap 5 during the first mailing. Once the envelope is opened after the first mailing, the second mailing flap 5 is folded out. The second mailing flap 5 covers the return addresser 10 on the front panel 1 of the envelope. During the second mailing the front of the envelope will look like the front of the envelop shown in FIG. 9. 
     In general, the front of the envelopes during first mailing can look like any of the envelopes shown in FIGS. 2a through 2c. The first mail return addresser 10 can be preprinted, a label or a window because it is covered. The first mail forward addresser 11 is preferably a window because is it not covered during the second mailing. The correct second mailing forward address could be provided on a return invoice that would show through the window. If the first mailing forward addresser 11 were preprinted on the envelope, a perforation around the forward addresser 11 could be provided on the front panel 1 and to provide the correct forwarding information for the second mailing, the perforated addresser 11 would be removed after the first mailing. 
     The fold 6 between the front panel 1 and the first mailing flap 4 could include a perforation for separation of the flap 4 during the second mailing. A fold guide 28 can be provided along the second mailing flap 5 to make sealing the envelope for the second mailing easier. The fold guide 28 can be either be a fold or a perforation. 
     As shown in FIGS. 22a through 35, the side flaps 3 are sealed most of the way, but include an unsealed portion to allow the first mailing flap 4 to be tucked inside the envelope for the second mailing. If the first mailing flap 4 were to be severed prior to the second mailing the unsealed portion of the side flaps 3 would not be important. However, the preferred embodiment is to include an unsealed portion. 
     Even though the second mailing flap 5 folds up on the outside of the envelope, the glue 27 is always hidden from the first mailing flap 4. This is important because if the glue 27 were not hidden from the inner surface of the first mailing flap 4 and excess moisture was applied during the first sealing, the two flaps 4 and 5 would stick together. 
     EXAMPLE 7 
     Referring now to FIGS. 22a and 22b, the inside and outside of Example 7 of a two way envelope that has a second mailing flap 5 folded outside the envelope is shown. The flap is folded twice to hide the glue 27 on the inner surface of the flap 5. FIG. 23 is a cut away view of the two way envelope showing the second mailing flap 5 on the outside of the envelope and folded twice inward toward the envelope. FIG. 24 is a cross sectional view that shows the second mailing flap 5 folded up during the first mailing. When the flap 5 is folded out during the second mailing the envelope will look the same as the envelope shown in FIG. 11. Some removable glue spots 25 are shown on the outer surface of the flap 5 near the fold between the flap 5 and the rear panel 2 to help the folding of the second mailing flap 5. 
     EXAMPLE 8 
     FIGS. 25a and 25b show the inside and outside of Example 8 of a two way envelope that has a second mailing flap 5 folded outside the envelope. FIG. 26 is a cut away view of the two way envelope showing the second mailing flap 5 on the outside of the envelope and folded outward away from the envelope. FIG. 27 is a cross sectional view that shows the second mailing flap 5 folded up during the first mailing. The flap 5 is folded once between the flap 5 and the rear panel 2 and again in the middle of the flap 5. The glue 27 is on the inner surface of the flap 5. When the flap 5 is folded out during the second mailing the envelope will look the same as the envelope shown in FIG. 11. Some removable glue spots 25 are shown on the inner surface of the flap 5 and the outer surface of the rear panel 2 to help the folding of the second mailing flap 5. 
     EXAMPLE 9 
     FIGS. 28a and 28b show the inside and outside of Example 9 of a two way envelope that has a second mailing flap folded outside the envelope similar to FIGS. 22a through 24, except that the first mailing flap 4 includes a tear strip 31 or notches 32 (described previously). The rear of the envelope during first mailing would look the same as the envelope shown in FIG. 23 except that a tear strip 31 or notches 32 would be provided as shown in FIGS. 13a and 13b. FIG. 29 is a cross sectional view that shows the second mailing flap 5 folded up during the first mailing. When the flap 5 is folded out during the second mailing the envelope will look the same as the envelope shown in FIG. 18. Some removable glue spots 25 are shown on the outer surface of the flap 5 and the outer surface of the rear panel 2 to help the folding of the second mailing flap 5. 
     EXAMPLE 10 
     FIGS. 30a and 30b show the inside and outside of Example 10 of a two way envelope that has a second mailing flap folded outside the envelope similar to FIGS. 25a through 27, except that the first mailing flap 4 includes a tear strip 31 or notches 32. The rear of the envelope during first mailing would look the same as the envelope shown in FIG. 26 except that a tear strip 31 or notches 32 would be provided as shown in FIGS. 13a and 13b. FIG. 31 is a cross sectional view that shows the second mailing flap 5 folded up during the first mailing. When the flap 5 is folded out during the second mailing the envelope will look the same as the envelope shown in FIG. 18. Some removable glue spots 25 are shown on the inner surface of the flap 5 and the lower outer surface of the rear panel 2 to help the folding of the second mailing flap 5. 
     EXAMPLE 11 
     FIGS. 32a and 32b show the inside and outside of Example 11 of a two way envelope that has a second mailing flap folded outside the envelope similar to FIGS. 22a through 24, except that the first mailing flap 4 includes a perforation and a string 33 and the application of glue is different. FIG. 33 is a rear view of the two way envelope showing the second mailing flap 5 on the outside of the envelope and folded inward toward the envelope and the perforation and a string 33. The cross sectional view that shows the second mailing flap 5 folded up during the first mailing looks the same as the envelope shown in FIG. 24 except the first mailing panel 4 would be slightly longer to accommodate the perforation and the string 33. When the flap 5 is folded out during the second mailing the envelope will look the same as the envelope shown in FIG. 18. Some removable glue spots 25 are shown on the outer surface of the flap 5 and the outer surface of the rear panel 2 to help the folding of the second mailing flap 5. 
     EXAMPLE 12 
     FIGS. 34a and 35b show the inside and outside of Example 12 of a two way envelope that has a second mailing flap folded outside the envelope similar to FIGS. 25a through 27, except that the first mailing flap 4 includes a perforation and a string 33 and the application of glue is different. FIG. 35 is a rear view of the two way envelope showing the second mailing flap 5 on the outside of the envelope and folded outward away from the envelope and the perforation and string 33. The cross sectional view that shows the second mailing flap 5 folded up during the first mailing looks the same as the envelope shown in FIG. 27 except the first mailing panel 4 would be slightly longer to accommodate the perforation and the string 33. Some removable glue spots 25 are shown on the inner surface of the flap 5 and the lower outer surface of the rear panel 2 to help the folding of the second mailing flap 5. 
     EXAMPLES 13-20 
     Examples 13 through 20 are similar to Examples 1-12, except that the first mailing return addresser 10 is located on the first mailing flap 4 which is attached to the rear panel 2 and folds over the top of the envelope and attaches to the front panel 1 during the first mailing. The second mailing flap 5 is attached to the front panel 1 and is folded on the outside of the two way envelope and covered by the first mailing flap 4 during the first mailing. 
     EXAMPLE 13 
     FIGS. 36a and 36b show the inside and outside of Example 13 of a two way envelope that has a second mailing flap 5 folded outside the envelope on the front side of the envelope. FIG. 37 is a front view of the two way envelope that shows the first mailing return addresser 10 on the front of the first mailing flap 4. FIG. 38 is a cut away view of the two way envelope showing the second mailing flap 5 on the outside of the envelope and folded outward away from the envelope. FIG. 39 is a cross sectional view through the envelope that shows the second mailing flap 5 folded up during the first mailing. 
     Removable glue in spots 26 or lines is provided on the first mailing flap 4 for sealing the envelope during first mailing. Moisture sensitive glue 27 is provided on the second mailing flap for sealing during the second mailing. Some removable glue spots 25 can be added on the inner and outer surfaces of the second mailing flap 5 to aid in the folding. The second mailing flap 5 is folded twice to hide the glue on the inner surface of the flap 5. 
     FIG. 40 is front view of the two way envelope with the second mailing flap 5 folded out for the second mailing. The front and rear of the envelope during the second mailing look like a normal one way mailing envelope. FIG. 41 is a cross sectional view through the envelope that shows the second mailing flap 5 folded out for the second mailing. The second mailing flap 5 could include a fold or perforation 28 to allow the flap 5 to fold over the top of the envelope more easily. 
     EXAMPLE 14 
     FIGS. 42a and 42b show the inside and outside of Example 14 of a two way envelope similar to Example 13. FIG. 43 is a front view of the envelope showing the second mailing flap 5 is folded inward toward the envelope as opposed to outward as in Example 13. FIG. 44 is a cross sectional view through the envelope shown in FIG. 43 that shows the second mailing flap folded up during the first mailing. The removable glue spots 25 on the second mailing flap are provided on the outside of the flap 5. 
     EXAMPLE 15 
     FIGS. 45a and 45b show the inside and outside of Example 15 of a two way envelope similar to Example 13 except that the first mailing flap 4 includes one extra fold line 6 to accommodate the notches or tear strip. FIGS. 46a and 46b are front views of the envelope showing the first mailing return addresser 10 on the front of the first mailing flap 5 with the optional notches or tear strip. FIG. 47 is a cut away view of the envelope showing the second mailing flap 5 folded outward away from the envelope like Example 13. 
     FIG. 48 is a cross sectional view through the envelope shown in FIG. 47 that shows the second mailing flap 5 folded up during the first mailing and the extra fold in the first mailing flap 4. The first mailing flap 4 includes moisture sensitive glue 27 on the outside which is then folded over to face the rear panel 2 to seal the envelope. Removable glue spots 25 are provided on the inside to aid in the folding of the flap. The portion of the first mailing flap 4 that include the moisture sensitive glue is not removed from the front of the envelope. 
     The first mailing flap 4 can be severed in a line parallel to the top edge of the envelope in the middle of the flap 4 or it could be removed entirely by severing it from the rear panel 2. The severance could be accomplished by notches in the flap 4 as shown in FIG. 46a, by a tear strip as shown in FIG. 46b, or a perforation and a string in the fold in the flap which would make the front look like FIG. 37. 
     FIG. 49 is front view of the two way envelope with the second mailing flap 5 folded out for the second mailing showing the portion of the first mailing flap 4 that remains attached to the front of the envelope. FIG. 50 is a cross sectional view through the envelope shown in FIG. 49 that shows the second mailing flap 5 folded out for the second mailing. 
     EXAMPLE 16 
     FIGS. 51a and 51b show the inside and outside of Example 16 of a two way envelope that is similar to Example 15 except that the second mailing flap 5 folded inward toward the envelope as opposed to away from the envelope. FIG. 52 is a cut away view of the envelope showing the second mailing flap 5 folded outward away from the envelope. FIG. 53 is a cross sectional view through the envelope shown in FIG. 52 that shows the second mailing flap folded up during the first mailing. Examples 15 and 16 are similar in the same way that FIGS. 13 and 14 are similar including the location of the removable glue spots 25 on the second mailing flap 5. 
     EXAMPLE 17 
     FIGS. 54a and 54b show the inside and outside of Example 17 of a two way envelope similar to Example 16 except that the first mailing flap 4 is severed from the rear panel 2 and folds down to provide the second mailing forward addresser 21. The severed first mailing flap 4 is secured by a pressure sensitive glue strip 35 provided on the bottom of the front panel 1. FIG. 55 is a front view of the envelope showing the pressure sensitive sealing strip 35 on the bottom of the front panel 1. FIG. 56 is a cut away view of the envelope showing the second mailing flap 5 on the outside of the envelope and folded inward toward the envelope. The cross sectional view of FIG. 56 would look like the envelope shown in FIG. 53. The envelope could include a perforation and a string in the fold line 6 between the rear panel 2 and the first mailing flap 4 to allow a clean severance. 
     FIG. 57 is front view of the envelope with the second mailing flap 5 folded out and the first mailing flap 4 folded down for the second mailing. FIG. 58 is a cross sectional view through the envelope shown in FIG. 57 that shows the second mailing flap 5 folded out and the first mailing flap 4 folded down for the second mailing. The second mailing flap 5 provides the second mailing return addresser 20 and the folded down first mailing flap 4 provides the second mailing forward addresser 21. 
     EXAMPLE 18 
     FIGS. 59a and 59b show the inside and outside of Example 18 of a two way envelope that is similar to Example 17 except that the second mailing flap 5 is folded outward away from the envelope as opposed to inward toward the envelope. FIG. 60 is a cut away view of the envelope showing the second mailing flap 5 folded inward toward the envelope and the pressure sensitive glue strip 35. The cross sectional view through FIG. 60 would look the same as the envelope shown in FIG. 48. Examples 17 and 18 are similar in the same way that FIGS. 16 and 15 are similar including the location of the removable glue spots 25 on the second mailing flap 5. 
     EXAMPLE 19 
     FIGS. 61a and 61b show the inside and outside of Example 19 of a two way envelope that is similar to Example 13 except that the first mailing flap is a bit longer and includes a perforation and a string 33 or a tear strip 31. FIGS. 62a and 62b are front views of the envelope showing the perforation and string 33 or a tear strip 31 for opening the envelope after the first mailing. The cross section of FIG. 62a or 62b would look like the envelope shown in FIG. 39 except that the first mailing flap 4 would be a little longer to accommodate the perforation and string 33 or the tear strip 31. 
     The second mailing flap 5 would be folded outwards away from the envelope as shown in FIG. 38. Likewise the glue is provided in the same position as shown in Example 13. 
     The first mailing flap 4 includes moisture sensitive glue 27 as opposed to removable glue spots and a portion of the first mailing flap 4 would remain on the front panel 1 once the flap 4 was severed. The front view of the second mailing would look like the envelope shown in FIG. 49. 
     EXAMPLE 20 
     FIGS. 63a and 63b show the inside and outside of Example 20 of a two way envelope that is similar to Example 19 except that the second mailing flap 5 folded inward toward the envelope as opposed to away from the envelope. The cut away view of the envelope showing the second mailing flap 5 folded inward toward the envelope would look the same as the envelope shown in FIG. 43. Examples 19 and 20 are similar in the same way that FIGS. 13 and 14 are similar including the location of the removable glue spots 25 on the second mailing flap 5. 
     EXAMPLES 21-29 
     Examples 21-29 are shown in FIGS. 64a-85b. In each of the examples 21-29, the second mailing flap 5 is integrated with the front panel 1. The first mailing return addresser 10 is provided on the first mailing flap 4. After the first mailing, the envelope is opened, the first mailing flap 4 is tucked inside the envelope. Then the second mailing flap 5 is used to seal the envelope for the second mailing. 
     EXAMPLE 21 
     FIGS. 64a and 64b show the inside and outside of Example 21 of a two way envelope. The second mailing flap 5 is provided on the top portion of the front panel 1. The front view of the envelope would look the same as the envelope shown in FIG. 37. FIG. 65 is a cross sectional view through the envelope that shows the sealed envelope during the first mailing. This envelope looks like a regular envelope through the cross-section, however, the first mailing information is provided on the side that would be the back of a regular envelope. 
     FIG. 66 is front view of the envelope that has been sealed for the second mailing. FIG. 67 is a cross sectional view through the envelope shown in FIG. 66 that shows the first mailing flap 4 tucked inside the envelope. The first mailing flap 4 is shown with removable glue spots 25 and could include a fold or a perforation parallel to the top edge in the middle of the flap 4 to allow it to tucked inside the envelope more easily. The second mailing flap 5 has moisture sensitive glue 27 for sealing for the second mailing. 
     EXAMPLE 22 
     FIGS. 68a and 68b show the inside and outside of Example 22 of a two way envelope that has a second mailing flap 5 that is integrated with the front panel 1 and folds inside the envelope. Example 22 is the same as the example 21 except the second mailing flap 5 is folded inward. FIG. 69 is a cut away view of the two way envelope showing the second mailing flap 5 on the inside of the envelope and folded inward toward the envelope. FIG. 70 is a cross sectional view through the envelope that shows the sealed envelope during the first mailing. 
     EXAMPLE 23 
     FIGS. 71a and 71b show the inside and outside of Example 23 a two way envelope that has a second mailing flap 5 that is integrated with the front panel 1 and folds inside the envelope. Example 23 is the same as example and 22 except the second mailing flap is a little longer and seals on the rear panel 2 of the envelope during the second mailing. FIG. 72 is a cross sectional view through the envelope that shows the sealed envelope during the first mailing. The second mailing flap 5 folds over the top of the envelope during the second mailing, along perforation 28. The front view and cross-section of the envelope during second mailing would look like the envelope shown in FIGS. 40 and 41. 
     EXAMPLE 24 
     FIGS. 73a and 73b show the inside and outside of Example 24 of a two way envelope that has a second mailing flap that is integrated with the front panel. Example 24 is the same as Example 21 except that the first mailing flap 4 is folded at the top and can include notches 32 or a tear strip 31. The front view of the envelope would look the same as the envelopes shown in FIGS. 37, 46a and 46b. FIG. 74 is a cut away view of the envelope showing the first mailing flap 4 folded toward the envelope and sealed. FIG. 75 is a cross sectional view through the envelope that shows the sealed envelope during the first mailing. 
     FIG. 76 is front view of the envelope that has been sealed for the second mailing showing that a portion of the first mailing flap 4 remains on the front panel 4 of the envelope. The first mailing flap would use moisture sensitive glue 27 to seal the envelope, and may include removable glue spots 25 to aid in folding. FIG. 77 is a cross sectional view through the envelope that shows the envelope sealed for the second mailing. 
     EXAMPLE 25 
     FIGS. 78a and 78b show the inside and outside of Example 25 a two way envelope that has a second mailing flap that is integrated with the front panel. Example 25 is the same as Example 22 except that the first mailing flap 4 is folded at the top and can include notches 32 or a tear strip 31 in the same way Example 24 is similar to Example 21. The front view of the envelope would look the same as the envelopes shown in FIGS. 37, 46a and 46b. FIG. 79 is a cut away view of the envelope showing the second mailing flap 5 folded inside the envelope and the first mailing flap 4 folded toward the envelope and sealed. FIG. 80 is a cross sectional view through the envelope that shows the sealed envelope during the first mailing. The front view and cross-section of the envelope during second mailing would look the same as the envelope shown in FIGS. 76 and 77. 
     EXAMPLE 26 
     FIGS. 81a and 81b show the inside and outside of Example 26 a two way envelope that has a second mailing flap that is integrated with the front panel. Example 26 is the same as Example 23 except that the first mailing flap 4 is folded at the top and can include notches 32 or a tear strip 31 in the same way Example 24 is similar to Example 21. The front view of the envelope would look the same as the envelopes shown in FIGS. 37, 46a and 46b. FIG. 82 is a cross sectional view through the envelope that shows the sealed envelope during the first mailing. The front view and cross-section of the envelope during second mailing would look the same as the envelope shown in FIGS. 49 and 50. 
     EXAMPLE 27 
     FIGS. 83a and 83b show the inside and outside of Example 27 of a two way envelope that has a second mailing flap 5 that is integrated with the front panel 1 and the first mailing flap 4 includes a perforation and a string 33. Example 27 is the same as Example 21 except that the first mailing flap 4 is a little longer and includes a perforation and a string 33. The front view of the envelope would look the same as the envelopes shown in FIGS. 62a and 62b. The cross sectional view through the envelope that shows the sealed envelope during the first mailing would look the same as the envelope shown in FIG. 65. 
     The front view of the envelope during the second mailing would look the same as the envelope shown in FIG. 76 which shows that a portion of the first mailing flap 4 remains on the front panel 4 of the envelope. The first mailing flap would use moisture sensitive glue 27 to seal the envelope, and may include removable glue spots 25 to aid in folding. The cross sectional view through the envelope that shows the envelope sealed for the second mailing would look the same as the envelope shown in FIG. 77. 
     EXAMPLE 28 
     FIGS. 84a and 84b show the inside and outside of Example 28 of a two way envelope that has a second mailing flap 5 that is integrated with the front panel 1 and the first mailing flap 4 includes a perforation and a string 33. Example 28 is the same as Example 22 except that the first mailing flap 4 is a little longer and includes a perforation and a string 33 in the same way Example 27 is similar to Example 21. The front view of the envelope would look the same as the envelopes shown in FIGS. 62a and 62b. The cross sectional view through the envelope that shows the sealed envelope during the first mailing would look the same as the envelope shown in FIG. 70. The front view and cross-section of the envelope during second mailing would look the same as the envelope shown in FIGS. 40 and 41. 
     EXAMPLE 29 
     FIGS. 85a and 85b show the inside and outside of Example 29 of a two way envelope that has a second mailing flap 5 that is integrated with the front panel 1 and the first mailing flap 4 includes a perforation and a string 33. Example 29 is the same as Example 23 except that the first mailing flap 4 is a little longer and includes a perforation and a string 33 in the same way Example 28 is similar to Example 22. The front view of the envelope would look the same as the envelopes shown in FIGS. 62a and 62b. The cross sectional view through the envelope that shows the sealed envelope during the first mailing would look the same as the envelope shown in FIG. 72. The front view and cross-section of the envelope during second mailing would look the same as the envelope shown in FIGS. 49 and 50. 
     EXAMPLES 30-41 
     Examples 30-41 of two way envelopes are shown in FIGS. 86a through 130. In each of the examples 30-41, the second mailing flap 5 is attached to the first mailing flap 4. The first mailing flap 4 is attached to the rear panel 2. The first mailing flap 4 is severed during opening and the second mailing flap 5 provides new information for the second mailing. The first mailing return addresser 10 is provided on the first mailing flap 4. 
     EXAMPLE 30 
     FIGS. 86a and 86b show the inside and outside of Example 30 of a two way envelope that has a second mailing flap 5 that is integrated with the first mailing flap 4. The first mailing flap 4 can include a perforation, a perforation and a string 33, notches 32 or a tear strip 31 to make opening the envelope after the first mailing easier. The front view of the envelope during first mailing would look like the envelopes shown in FIGS. 37, 46a and 46b. The first mailing flap 4 is attached to the rear panel 2. The second mailing flap 5 is attached to the first mailing flap 4 and includes a fold between the flap 5 and the first mailing flap 4 and another fold in the middle of the flap 5. FIG. 87 is a cut away view of the envelope showing the second mailing flap 5 folded outside the envelope away from the envelope. FIG. 88 is a cross sectional view through the envelope that shows the sealed envelope during the first mailing. 
     The second mailing flap 5 includes moisture sensitive glue 27 on the outside of the flap 5 adjacent to the first mailing flap 4 such that when the flap 5 is folded the glue 27 can seal the envelope during the first mailing. After the first mailing the first mailing flap 4 is severed from the second mailing flap 5 along fold 6a. The second mailing flap 5 is folded over the top of the envelope and sealed with the moisture sensitive glue 27 provided at the top of the flap 5. The second mailing return addresser 20 is provided on the second mailing flap 5. FIG. 89 is front view of the envelope that has been sealed for the second mailing. FIG. 90 is a cross sectional view through the envelope that shows the envelope sealed for the second mailing. Removable glue spots 25 can be added to make the folding of the second mailing flap 5 easier. 
     EXAMPLE 31 
     FIGS. 91a and 91b show the inside and outside of Example 31 of a two way envelope that has a second mailing flap that is integrated with the first mailing flap. Example 31 is the same as Example 30 except that second mailing flap 5 is folded toward the envelope rather than away from the envelope during the first mailing. FIG. 92 is a cut away view of the envelope showing the second mailing flap 5 folded outside the envelope toward the envelope. FIG. 93 is a cross sectional view through the envelope that shows the sealed envelope during the first mailing. The removable glue spots 25 provided on the second mailing flap 5 are on the outside of the envelope rather than on the inside. The front view during the first mailing and the front view and cross sectional view during second mailing would look the same as Example 30. 
     EXAMPLE 32 
     FIGS. 94a and 94b show the inside and outside of Example 32 of a two way envelope that has a second mailing flap 5 that is integrated with the first mailing flap 4. Example 32 is the same as Example 30 except that the second mailing flap 5 is slightly larger and folds over the top of the envelope during second mailing. FIG. 95 is a cut away view of the envelope showing the second mailing flap 5 folded outside the envelope away from the envelope. FIG. 96 is a cross sectional view through the envelope that shows the sealed envelope during the first mailing. FIG. 97 is front view of the envelope that has been sealed for the second mailing. FIG. 98 is a cross sectional view through the envelope that shows the envelope sealed for the second mailing. 
     EXAMPLE 33 
     FIGS. 99a and 99b show the inside and outside of Example 33 of a two way envelope that has a second mailing flap 5 that is integrated with the first mailing flap 4. Example 33 is the same as Example 31 except that the second mailing flap 5 is slightly larger and folds over the top of the envelope during second mailing. FIG. 100 is a cross sectional view through the envelope that shows the sealed envelope during the first mailing showing the second mailing flap 5 folded outside the envelope toward the envelope. The front view and cross sectional view of the envelope during the second mailing would look the same as the envelope shown in FIGS. 97 and 98. 
     EXAMPLE 34 
     FIGS. 101a and 101b show the inside and outside of Example 34 of a two way envelope that has a second mailing flap 5 that is integrated with the first mailing flap 4. The front view of the envelope during first mailing would look like the envelope shown in FIG. 37. The first mailing flap 4 is attached to the rear panel 2. The second mailing flap 5 is attached to the first mailing flap 4 and includes a fold between the flap 5 and the first mailing flap 4 and another fold in the middle of the flap 5. FIG. 102 is a cut away view of the envelope showing the second mailing flap 5 folded outside the envelope away from the envelope. FIG. 103 is a cross sectional view through the envelope that shows the sealed envelope during the first mailing. 
     The second mailing flap 5 includes moisture sensitive glue 27 on the outside of the flap 5 adjacent to the first mailing flap 4 such that when the flap 5 is folded the glue 27 can seal the envelope during the first mailing. During the first mailing, the second mailing return addresser 20 is hidden by the flaps 4 and 5. After the first mailing the first mailing flap 4 is severed from the second mailing flap 5. The second mailing flap 5 is folded down over the first mailing forward addresser 11 and sealed with the moisture sensitive glue 27 provided at the top of the inside of flap 5. A perforation or fold 40 can be provided to make folding the second mailing flap 5 down easier. The second mailing forward addresser 21 is provided on the second mailing flap 5. The first mailing flap 4 is removed from the envelope or tucked into the inside of the envelope and moisture sensitive glue 27 is provided on the top of the inside of the front panel 1 for resealing the envelope for the second mailing. Once the first mailing flap 4 is removed or tucked inside the envelope and the second mailing flap 5 is folded down, the second mailing return addresser 20 is no longer hidden. FIG. 104 is front view of the envelope that has been sealed for the second mailing. FIG. 105 is a cross sectional view through the envelope that shows the envelope sealed for the second mailing. Removable glue spots 25 can be added to make the folding of the second mailing flap 5 easier. 
     EXAMPLE 35 
     FIGS. 106a and 106b show the inside and outside of Example 35 of a two way envelope that has a second mailing flap 5 that is integrated with the first mailing flap 4. Example 35 is the same as Example 34 except that a portion of the front panel is folded over to provide a second sealing flap 39. FIG. 107 is a cut away view of the envelope showing the second mailing flap 5 folded outside the envelope away from the envelope and the front panel 1 folded inside the envelope. FIG. 108 is a cross sectional view through the envelope that shows the sealed envelope during the first mailing. After the first mailing the second sealing flap 39 would be folded up and used to reseal the envelope. The front and cross sectional views during the second mailing would look the same as the envelope shown in FIGS. 104 and 105. 
     EXAMPLE 36 
     FIGS. 109a and 109b show the inside and outside of Example 36 of a two way envelope that has a second mailing flap 5 that is integrated with the first mailing flap 4. Example 36 is the same as Example 35 except that the second sealing flap 39 is longer and folds over the top of the envelope during the second mailing. FIG. 110 is a cut away view of the envelope showing the second mailing flap 5 folded outside the envelope away from the envelope and the second sealing flap 39 that is attached to the front panel 1 folded inside the envelope. FIG. 111 is a cross sectional view through the envelope that shows the sealed envelope during the first mailing. FIGS. 112 and 113 are a front view and cross sectional view of the envelope that has been sealed for the second mailing showing the second sealing flap 39 folded over the top of the envelope. The second sealing flap 39 can include a fold or perforation to allow the flap 39 to fold over the top of the envelope more easily. As is shown, the first mailing flap 4 can be removed after the first mailing. 
     EXAMPLE 37 
     FIGS. 114a and 114b show the inside and outside of Example 37 of a two way envelope that has a second mailing flap 5 that is integrated with the first mailing flap 5 and a second sealing flap 39 attached to the front panel 1. Example 37 is the same as Example 36 except the second sealing flap 39 folds on the outside of the envelope during the first mailing. The front view of the envelope during first mailing would look the same as the envelope shown in FIG. 37. FIG. 115 is a cut away view of the envelope showing the second mailing flap 5 folded outside the envelope away from the envelope and the second sealing flap 39 folded outside the envelope away from the envelope. FIG. 116 is a cross sectional view through the envelope that shows the sealed envelope during the first mailing. The second sealing flap 39 has the second mailing return addresser 20. The front view and cross sectional view during the second mailing would look the same as the envelope shown in FIGS. 112 and 113. 
     EXAMPLE 38 
     FIGS. 117a and 117b show the inside and outside of Example 38 of a two way envelope that has a second mailing flap 5 that is integrated with the first mailing flap 4 and a second sealing flap 39 attached to the front panel 1. Example 38 is the same as Example 37 except the second sealing flap 39 is folded toward the envelope rather than away from the envelope. FIG. 118 is a cut away view of the envelope showing the second mailing flap 5 folded outside the envelope away from the envelope and the second sealing flap 39 folded outside the envelope toward the envelope. FIG. 119 is a cross sectional view through the envelope that shows the sealed envelope during the first mailing. 
     EXAMPLE 39 
     FIGS. 120a and 120b show the inside and outside of Example 39 of a two way envelope that has a second mailing flap 5 that is integrated with the first mailing flap 4 and a second sealing flap 39 attached to the front panel 1. The second mailing flap 5 is actually the back of the first mailing flap 4. A pressure sensitive adhesive strip 35 is provided on the bottom of the front panel 1. The front view of the envelope during the first mailing would look like the envelope shown in FIG. 55. FIG. 121 is a cut away view of the envelope showing the second sealing flap 39 folded inside the envelope. The first and second mailing flaps 4 and 5 include a fold 6 near the top. The top of the flaps 4 and 5 is folded over and can be held in place with removable glue spots 25. Moisture sensitive glue 27 is provided on the top of the first mailing flap 4 and is used to seal the envelope for the first mailing. FIG. 122 is a cross sectional view through the envelope that shows the sealed envelope during the first mailing. 
     After the first mailing, the first mailing flap 4 is separated from the rear panel 2 and is folded down over the first mailing forward addresser 11. The second mailing forward addresser is provided on the second mailing flap 5 which is merely the back of the former first mailing flap 4. The second mailing forward addresser 21 is provided on the second sealing flap 39. The front view during the second mailing looks the same as the envelope shown in FIG. 112. FIG. 123 is a cross sectional view through the envelope that shows the envelope sealed for the second mailing. 
     EXAMPLE 40 
     FIGS. 124a and 124b show the inside and outside of Example 40 of a two way envelope that has a second mailing flap 5 that is integrated with the first mailing flap 4 and a second sealing flap 39 attached to the second mailing flap 5. The second mailing flap 5 is actually the back of the first mailing flap 4. A pressure sensitive adhesive strip 35 is provided on the bottom of the front panel 1. The front view of the envelope during the first mailing would look like the envelope shown in FIG. 55. FIG. 125 is a cut away view of the envelope showing the second mailing flap 5 and the second sealing flap 39 folded outside the envelope toward the envelope. FIG. 126 is a cross sectional view through the envelope that shows the sealed envelope during the first mailing. 
     After the first mailing, the first mailing flap 4 is separated from the rear panel 2 and is folded down over the first mailing forward addresser 11. The second mailing forward addresser 21 is provided on the second mailing flap 5 which is merely the back of the former first mailing flap 4. The second mailing return addresser 20 is provided on the second sealing flap 39 which folds up and over the envelope and seals on the rear panel 2 for the second mailing. The front view during the second mailing looks the same as the envelope shown in FIG. 4. FIG. 127 is a cross sectional view through the envelope that shows the envelope sealed for the second mailing. 
     EXAMPLE 41 
     FIGS. 128a and 128b show the inside and outside of Example 41 of a two way envelope that has a second mailing flap 5 that is integrated with the first mailing flap 4 and a second sealing flap 39 attached to the second mailing flap 5. Example 41 is the same as example 40 except that the second sealing flap 39 is folded away from the envelope rather than towards the envelope. FIG. 129 is a cut away view of the envelope showing the second mailing flap 5 and the second sealing flap 39 folded outside the envelope away from the envelope. FIG. 130 is a cross sectional view through the envelope that shows the sealed envelope during the first mailing. 
     It is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments are not intended to limit the scope of the claims, which themselves recite those features regarded as essential to the invention.
The present invention includes a two way envelope that has a front panel, a rear panel, side flaps and a first mailing flap that seals the envelope during the first mailing like any other normal envelope. In addition to these standard features, the envelopes of the present invention include a second mailing flap which folds out to cover a portion of the first mailing information and display second mailing information. The second mailing flap can seal the envelope for the second mailing or a second mailing sealing flap can be provided. The two way envelope differs from the previous two way envelopes primarily in the ease with which the second mailing flap is folded out. The sides of the envelope are closed from the bottom of the envelope to only a portion of the way to the top. The fact that the top portion of the sides are not sealed allows the front and rear panels to be spread apart and the second mailing flap can be removed from between the two panels or the first mailing flap can be inserted with ease. The present invention also includes envelopes that have a second mailing flap or a second sealing flap folded on the outside of the envelope and covered by the first mailing flap during the first mailing. Once the envelope is opened, the second mailing flap or second sealing flap are extremely easy to unfold. In some embodiments, the first mailing information is provided on what would normally look like the rear of the envelope.