What is a Water Mark?

   Water Mark, in ordinary language, the mark or limit of the rise of a flood; the mark indicating the rise and fall of the tide. In paper making, any distinguishing device or devices indelibly stamped in the substance of a sheet of paper while yet in a damp or pulpy condition. The device representing the water mark is stamped in the fine wire gauze of the mold itself. The design is engraved on a block. from which an electrotype impression is taken; a matrix, or mold, is similarly formed from this. These are subsequently mounted on blocks of lead or gutta-percha to enable them to withstand the necessary pressure and serve as a cameo and intaglio die, between which the sheet of wire gauze is placed to receive an impression in a stamping press. The water marks used by the earlier paper makers have given names to several of the present standard sizes of paper, as pot, foolscap, crown, elephant, fan, post.