It is created using a pattern of wire sewn into the mould on which the sheet of pulp is dried – the paper which settles above the wires is thinner, and so more translucent. The image usually represents the papermaker’s trademark design or logo, sometimes with a name, initials or date. Although more common in historical papers, (handmade) modern specialist printmaking papers often also contain a watermark.
Watermark
An image or mark in a sheet of paper (usually the papermaker's trademark) visible when viewed by transmitted light