This catalog covers U.S. postal stationery envelopes, wrappers and letter sheets overprinted and used for various non-postal purposes. One purpose of "SPECIMEN" stationery was for use as bidder samples.One purpose of "SPECIMEN" stationery was for use as bidder samples. A second purpose of "SPECIMEN" stationery was to promote the use of postal stationery. A third purpose of "SPECIMEN" stationery was for distribution to prominent government officials, important dignitaries, the Universal Postal Union, or similar purposes. A fourth purpose of "SPECIMEN" stationery was periodic quality control samples taken from the production lines for government officials to validate the quality of envelopes being produced.