The “R. Mutt 1917” signature
Brushed in black paint on the outer rim of the form, toward the lower left as photographed
The only authorial mark on a factory object is a fake name. Duchamp said “Mutt” came from the J. L. Mott Iron Works, a well-known New York plumbing manufacturer, which he altered to “Mutt” with a nod to the popular comic strip Mutt and Jeff, and that “R.” stood for Richard, French slang for a moneybags. Whether the urinal really came from Mott is itself disputed, a point that feeds the rival authorship claim (Mott may not have stocked this model). The signature is the entire claim of authorship, painted onto something the artist did not make.