6c Proprietary revenue stamp trial color proof
In 1875, the Bureau of Internal Revenue awarded the printing contract for revenue stamps to the National Bank Note Company. Joseph R. Carpenter had previously held the contract. National Banknote prepared a new series of proprietary stamps, commonly referred to as the "second proprietary issue," in denominations of one-cent, two-cent, three-cent, four-cent, five-cent, and six-cent. The stamps were issued between October, 1875 and the elimination of proprietary taxes on July 1, 1883. The federal government had imposed the proprietary taxes on items such as matches, proprietary medicines, and perfumes to pay for the Civil War.
Three printers produced the second issue proprietary stamps. The National Bank Note Company produced the stamps from1875 through February 1879, when that company was consolidated into the American Bank Note Company. American Bank Note held the printing contract until October, 1880, when the Bureau of Engraving and Printing assumed responsibility for the production of proprietary stamps. In 1881, the Bureau added a ten-cent denomination proprietary stamp to the series.
This trial color proof in brown ink is printed on india paper mounted on a card and was submitted to the Commissioner of Internal Revenue for approval. The proof, also known as an "approval model," was approved on September 29, 1875. Between November 3, 1875, and May 26, 1883, 5,423,951 6-cent proprietary stamps were issued. The stamps were printed in two colors, violet and blue.
Turner, George T., Essays and Proofs of United States Internal Revenue Stamps: A compilation with relative prices, 1974, Arlington, Massachusetts: Bureau Issues Association, Inc.
Toppan, G.L., H.E. Deats and A. Holland. 1899. An Historical Reference List of the Revenue Stamps of the United States. Boston: Boston Philatelic Society. Reprinted as The Boston Revenue Book. Lawrence, Massachusetts: Quarterman Publications, 1979.