Watermark is an image or signet that manufacturers imperceptibly add to a piece of paper as an identifying mark that protects copyright.In the industry of the printing process prior to the digital era, paper manufacturers had to cut a rubber die and place it on a large drum. They would add sulfuric acid to wood pulp in a vat of water to break down the fibers of the wood, which created a substance called slurry.
Manufacturers could pour the slurry onto a screen. As it dried, the slurry would begin to form paper. At this point, the manufacturers could pull the slurry through two drums, and the one with the rubber die cut would press the water from the paper, resulting in the watermark.
In today’s world of digital printing, the process to create a watermark has changed. You can use several tools to watermark paper or photographs.