Also called dry stamp or seal, most often done in the form of an embossing near the lower edge of a print by an artist, workshop, publisher, or printer. This "chop" may be used to authenticate a print.

See Blind Stamp

A small embossed seal or impression on a print, generally indicating the printer or artist.

An identification mark punched into a coin by a Chinese merchant. The mark is used to indicate that the metal of the coin has been tested and is of a known quality.

A symbol added to money by someone other than the government which issued it to indicate authenticity

A small mark punched onto coins by merchants who “certified” the coin's authenticity and value