Hand signed with black by Andy Warhol on a real 1 dollar bill ‘Silver Certificate Blue Seal’, series 1957A*. Numbered and with embossed and ink stamp © Andy Warhol. Hologram 'verification of authenticity' on the back. 15,6 x 6,7 cm. With certificate from 'The Andy Warhol Foundation for the Visual Arts'. *A silver certificate dollar bill was a legal tender issued by the United States government. When they were first issued, certificate holders could redeem them for a certain amount of silver.