Image result for victorian stamp watermarkWatermarks are a design that are put in paper by the manufacturer to identify the paper as their product. They are an outgrowth of the earliest paper which is called laid paper. Laid paper is produced by allowing the paper pulp particles to coagulate on a bed that is a screen made up of closely knit small parallel rods of metal. The pulp coalesces in a pattern of thickness and thinness that mimics the bed that it was made on. When paper technology advanced and paper was produced on a cloth bed (where the fibers had been woven-thus "wove" paper) paper had no thick-thin variance within the sheet. Paper makers found that they could put a pattern in the cloth bed that the paper was formed on and, when the fibers settled, the pattern would show up in reverse as an area where the paper was thinner. These were the first watermarks.

When stamps were first proposed the major objection to their being issued was fear of counterfeiting and washing and reuse. It was for this reason that the Penny Black was engraved with difficult to duplicate lathe work in the background and why check letters were used in the corners. An additional precaution was the use of watermarked paper. The goal was to raise the costs of making a convincing counterfeit and to make it that one needed access to sophisticated technology in order to do so. But watermarked paper has always proved a problem in printing. The large crown watermark of the Penny Black made it difficult to center the plate on the sheet of paper for printing and made the the printing of the design itself more difficult ( This soon led to the smaller crown watermark within a few years). So difficult do watermarks make the printing process that most countries' first issues are not on watermarked paper (the United States didn't watermark its postage stamps until 1894) and it wasn't until late Nineteenth Century experience indicated that postal forgeries were indeed a problem that most countries began to use them. As printing technology has become more sophisticated and as mass users of mailing have moved to meters, fear of large scale counterfeiting has lessened to the point that few major countries still use watermarked paper in the production of their stamps.