a chair 20 ( fig1 ) embodying the present invention includes a cushioned seat 21 and a cushioned back 22 . the details of the support structure forming the present seat and back are disclosed in u . s . pat . no . 5 , 871 , 258 , issued feb . 16 , 1999 , entitled chair with novel seat construction , and the entire contents of the &# 39 ; 258 patent are incorporated herein for the purpose of providing a complete disclosure of the same . in the present invention , the seat 21 ( fig3 ) has a seat support structure 23 with an upwardly oriented face covered by a fabric covering 24 for aesthetics . an arrangement of several male snap connectors 25 are secured in recesses 25 ′ to the seat support structure 23 , such as by attaching the snap connectors 25 to a resilient polymeric seat shell of the support structure 23 . a seat cushion assembly 26 includes a mating pattern of mating female snap connectors 27 that are configured and arranged to snappingly engage the male snap connectors 25 . by this arrangement , the seat cushion assembly 26 can be snap - attached to the seat support structure 23 for quick removal , such as for washing , dry - cleaning , repair , or maintenance . the fabric covering 24 covers the seat support structure 23 ( fig4 ) for aesthetic reasons when the seat cushion assembly 26 is removed , and also covers the seat support structure 23 for functional reasons , such as to prevent articles from falling into the mechanisms within the seat support structure 23 . preferably , the covering 24 is a durable material that will not easily rip or wear . where the fabric covering 24 is sufficiently strong , the snap connectors 25 can be attached only to the covering 24 , and edges of the covering 24 are adhered or otherwise secured to the seat support structure 23 . however , in a preferred form , the snap connectors 25 extend through and are secured in recesses 25 ′ to a flexible plastic shell that forms part of the seat support structure 23 . the seat cushion assembly 26 ( fig6 a ) includes a cushion 28 , a top covering 29 , and a bottom covering 30 . the cushion 28 can be a conventional polyurethane resilient foam , or can be a non - woven resilient fibrous material , or can be any reasonable material capable of providing resilient comfortable support to a seated user . the top covering 29 can be a manufacturer - chosen covering material or a customer &# 39 ; s own material . where a customer &# 39 ; s own material is used , a secondary stabilizing covering sheet 31 is used to provide integrity to the assembly . the bottom covering 30 must provide stable support for the snap connectors 27 , both so that the snap connectors 27 do not rip out of the covering 29 during pull - off of the seat cushion assembly 26 , and also so that the arrangement of snap connectors 27 stay in a dimensionally accurate position so that they can be easily re - attached to the other connectors 25 , even though it is a “ blind ” process . preferably the bottom covering 30 is a sheet of nonwoven fabric having a stretch of less than 5 %. for example , a 10 - 15 ounce non - woven sheet of polyester cloth can be used for this purpose . notably , the combination of the seat cushion assembly 26 snap - attached to the seat support structure 23 provides a novel , crevice - shaped appearance at a location 26 ′ ( fig6 ) sometimes referred to as a “ throw - rug ” type look . this “ look ” provides a novel “ relaxed ” appearance that is well - liked by computer operators and “ high - tech ” consumers . the seat cushion assembly 26 is a separate unit that is easily removed by pulling on the assembly 26 in direction “ a ” ( fig6 ) and can be easily re - attached by pressing through the cushion 28 against the snap connectors 27 . this arrangement greatly improves the ability of a chair manufacturer to competitively make chairs that incorporate customer &# 39 ; s own materials , because the cushion assembly 26 is stable and thus does not depend on the customer &# 39 ; s own material for strength or integrity . further , the customer &# 39 ; s own materials can be used without major logistic problems , since the cushions are separable and can be shipped from separate locations . for example , the cushions can be prepared at a local manufacturing site separate from the chair manufacturing plant . the present arrangement is considered to have surprising and unexpected qualities of dependability and reliability , even where customer &# 39 ; s own materials are used that do not have the requisite strength and other properties normally required by customers and chair manufacturers . alternatively , it is noted that the snap connectors 27 can extend through the cushion 28 and be located in depressions in the fabric 29 . three zippers 30 ′ ( fig4 ) are provided in the bottom covering 30 so that the cushion 28 can be stuffed into the seat cushion assembly . notably , one or more of the zippers 30 ′ can be replaced by hook - and - loop material , snaps , or other attachment means to reduce cost and facilitate assembly . the back 22 ( fig4 ) includes a back support structure or shell 35 and a back cushion assembly 36 . the back cushion assembly 36 includes a cushion 38 , a front covering 39 , and a back covering 40 . a crescent - shaped section of material 41 is sewn along a top edge of the coverings 39 and 40 to form a top seam 42 and a downwardly facing pocket or sock - like cavity 41 ′. the seam 42 can be created in numerous ways , three of which are illustrated . in fig7 the seam 42 is created by sewing edges of the three materials 39 , 40 , and 41 together , with all edges facing a same inward direction . in fig7 a , the three edges are rolled before sewing , which creates a smoother and more rounded appearance where the seam 42 ′ is not emphasized . in fig7 b , the edges of the materials 39 and 40 are sewn together at a first seam 42 ″, with the edges overlapping and facing in opposite directions . the back covering 40 is then sewn along a separate seam 43 to the crescent - shaped section of material 41 at a location spaced below the seam 42 ″. this creates a visual separation at location 43 ′ along its edges that is reminiscent of the “ throw - rug ” look discussed above , such that the combination of the snap - attached seat cushion of fig6 and the back cushion of fig7 a is very attractive and believed to be non - obvious in appearance . a bottom edge of the back cushion assembly 36 ( fig8 ) includes a zipper 44 with a top strip 45 sewn to a lower edge of the back covering 40 and a bottom strip 46 . the bottom strip 46 is sandwiched together with bottom edges of the front covering 39 and a stretchable elastic strip 47 in an inwardly extending orientation and then sewn together . the elastic strip 47 is highly stretchable , such as 200 % elongation or more . it includes a stiff strip 48 sewn along its lower edge . a thickened section 49 extends along a lower portion of the back shell 35 ( i . e . its back shell ), and includes a downwardly facing recess 50 . the elastic strip 47 is stretched and the stiff strip 48 is rolled over and tucked into the recess 50 while maintaining tension on the elastic strip 47 . this pulls the back cushion assembly 36 downwardly . this tension is important because a center of panel 54 ( i . e . the lumbar region )( fig4 ) of the back shell 35 is flexible . thus , when the back shell 35 is flexed to a more planar condition , the back cushion assembly 36 must “ absorb ” some of the excess material . the elastic strip 48 helps accomplish this purpose . in fig8 all edges of materials 39 , 46 and 47 extend inwardly in the same direction . in fig8 a , the strip 46 extends downwardly . this creates a “ puffy ” condition such that a lower edge of the cushion assembly 36 bellows out in a forward direction . this creates a “ throw - rug ” appearance complimentary of the structure shown in fig6 and 7b , although it is noted that the lower edge of the back cushion assembly 36 is so low that it is not particularly easy to see . in fig8 a , there is shown a fire - resistant material 51 that overlays a front of the elastic strip 48 . the fire - resistant material 51 is sewn loose to the elastic strip 48 when the elastic strip 48 is in a relaxed state , so that when the elastic strip 48 is stretched , the fire resistant material 51 does not limit stretching the elastic strip 48 . when attached and the back shell 35 is in its natural concave condition , the fire resistant material 51 is basically in a semi - taut condition . when the back shell 35 is flexed toward a planar condition , the fire resistant material 51 becomes loose , but this is not a problem since a person seated in the chair covers up an objectionable appearance . the fire - resistant material 51 is included when a local ordinance or law requires that chairs be resistant to fire damage . a vest or back covering 52 ( fig9 - 11 ) includes a semi - transparent front panel 53 of material sewn to a crescent - shaped rear panel 54 ( fig1 ) of similar material to form a sock - like cavity 41 ′. the particular material of panels 53 and 54 are sold under a tradename “ powernet ” by milliken & amp ; company , and are warp knit , gauge 64 gg , 85 % nylon and 15 % lycra , with a square weight of 4 . 2 per yard . the material can be colored to match chair aesthetics , and has an elasticity of about 10 % to 25 %. they provide a see - through property where the images through the material are visible and distinguishable , but have a ghost - like quality . an important aspect is that they are transparent , semi - transparent or translucent so that the horizontal slots 55 in the lumbar region 56 can be seen , both for aesthetics and function . also , this allows the position of a vertically - adjustable lumbar panel ( not specifically shown ) between the shell 35 and the vest 52 can be seen . at the same time , the panel 53 prevents a seated user &# 39 ; s back from being pinched within the slots 55 as the seated user flexes their lower back . attachment of the vest 52 is similar to that of back cushion assembly 36 . specifically , the back covering 52 is pulled downwardly onto a top of the back support structure 35 in direction “ b ” ( fig1 ). a stiff strip 48 sewn along a lower edge of the panel 53 is rolled and tucked into the recess 50 ( fig8 b ). the material of panel 53 is sufficiently elastic to stretch and keep tension on the material of panel 53 even when the back shell 35 is flexed toward a more planar condition . in one form , a back cushion assembly is provided that can be pulled downwardly in direction “ b ” ( fig4 ) onto a back support structure for assembly . the back cushion assembly includes a top section forming a sock that engages the back support structure , and a stretch fabric strip along its bottom edge that assists in retaining the back cushion assembly to the back , and further potentially includes a fire - resistant strip that overlays the stretch fabric strip to reduce damage in the event of a fire . to remove the back cushion assembly for cleaning , the procedure is reversed . in another form , a removable fabric vest is provided that is configured to pull downwardly over the back ( fig1 ) and releasably attach to a bottom edge of the back . the vest covers a majority of the face of the back and , in a preferred form , is of a see - through material such that horizontal slots in the back can be seen . to remove the vest , the above procedure is reversed . a seat cushion assembly is provided that snap - attaches to a seat support structure . to remove the seat cushion assembly , the procedure is reversed . accordingly , the seat cushion and the back cushion ( or the back vest ) can be quickly and easily removed for cleaning ( dry - cleaning or washing ), repair , maintenance , and sanitizing , and then reinstalled quickly and easily . also , customer &# 39 ; s own materials can be easily used in the present inventive arrangement . a hanger 65 ( fig1 - 14 ) is provided that is configured to releasably hold an extra vest 52 or back cushion assembly 36 in a non - wrinkling hung - up position . multiple vests 52 may be sold for a given chair , and chair owners will want to store these vests in a manner that prevents wrinkling or that facilitates drying or display . the present hanger 65 accomplishes that purpose . the hanger includes a bottom horizontal runner 76 and stiffening flange 77 . side wings 78 and 80 extend arcuately upwardly from ends of the runner 76 , and inwardly angled stiffeners 79 and 81 extend from the side wings 78 and 80 toward a center of the runner 76 . a vertical runner 82 extends up from the center of the runner 76 , and includes a hooked section 83 for engaging a coat - hook or clothes - bar . the sections 83 , 82 , 76 , 77 and 79 have a round cross section for optimal material flow , such that they define the equivalent of runners in the molding dies for the hanger 65 . while the sections 77 , 79 and 81 are relatively flat for reduced material consumption and to prevent distortion of the hanger portions forming the pocket . the wings 78 and 80 form an arc that is similar to a top edge of the back shell 35 . the vest 52 is hung on the hanger 65 by placing the members 78 , 79 , 80 and 81 into the cavity , but with the panels 53 and 54 of the vest 52 ( or of the back covering 40 ) being positioned on one side of the vertical runner 82 . the panel 54 ( or back covering 40 ) extends through spaces 84 and 85 when the vest 52 is hung on hanger 65 . one or more snaps or fastening devices 86 are provided on flange 77 so that an extra seat cushion assembly 26 can be snap - attached to the hanger 65 and supported thereon . in the foregoing description , those skilled in the art will readily appreciate that modifications may be made to the invention without departing from the concepts disclosed herein . such modifications are to be considered as included in the following claims , unless these claims by their language expressly state otherwise .