Penny Black print run was 286,700 sheets, containing a total of 68,808,000 stamps. Many were saved, and in used condition they remain readily available to stamp collectors. The only known complete sheets of the Penny Black are owned by the British Postal Museum. In addition to the general issue of the Penny Black, a similar stamp intended for official mail was produced, with the letters "V" and "R" replacing the crosses in the top corners. Because the general public quickly accepted the postage stamps and ridiculed the Mulready stationery produced at the same time, vast supplies of Mulready letter sheets were given
Penny Black up to to be delivered at a flat rate of one penny, regardless of distance. Postal delivery systems using what may have been adhesive stamps existed before the Penny Black. The idea had at least been suggested earlier in the Austrian Empire, Sweden, and possibly Greece. On 13 February 1837, Sir Rowland Hill proposed to a government enquiry both the idea of a pre-paid stamp and a pre-paid envelope, a separate sheet folded to form an enclosure for carrying letters. Hill was given a two-year contract to run the new system, and together with Henry Cole he announced a competition