The 24-cent Washington 1861 issue, which had some of the most intricate frame engravings of any U.S. stamp to that date, is known for its many different color shades. None was the result of a separate printing or different plate, a circumstance that only exacerbates the conundrum of their occurrence. The most common shades are red lilac and brown lilac. Steel blue, violet, and pale gray violet shades are far rarer. Engravers for this stamp were William Marshall (who also engraved the portrait for the 10- and 12-cent 1861 issues), William D. Nichols, and Cyrus Durand (the frame engravers).Engraver Cyrus Durand and his younger brother, Asher Durand, enjoyed notable careers. Cyrus invented a machine that could create intricate lathe work for banknotes, which was later used in stamp engraving. Asher engraved the Washington portrait for the Rawdon, Wright, Hatch & Edson 1847 Issue. Both brothers actually engraved portraits of George Washington for postage stamps, and they were the only engravers of his portrait living during Washington's lifetime. Born in 1788, Cyrus was twelve-years-old when Washington died (1799); Asher was age three. Cyrus was also the only stamp engraver alive concurrent with Benjamin Franklin, who died in 1790.The 24-cent Washington typically paid the single-weight letter rate to England until January 1, 1868, when the rate was reduced to twelve cents. Otherwise, the 24-cent stamp was used in combination with other denominations to fulfill greater weight and foreign destination rates. National Bank Note Company printed over 500,000 24-cent Washington stamps. This count includes all shades.Alexander T. Haimann, National Postal Museum. Stamp comes with certification from The American Philatelic Expertizing Service #154234, Catalog name 24c steel blue variety '61, Catalog number Scott US 70-b, Catalog value $9,000, Unused o.g. Estimate $15,000 - $25,000 Starting Bid $5,000