Edge Characteristics of Commercially Produced Paper Stock

The commercial production of paper items still involves the use of large guillotine blades to cut through thick stacks of paper stock, tablets, notebook filler paper, steno pads, and similar paper products. During the sharpening process and subsequent use, the blades acquire grind marks and nicks, and as a result, take on their own uniqueness. Depending on the thickness, type of paper stock, and frequency of use, these blades must be sharpened relatively frequently. When the blades are removed and sharpened, their unique features are removed. New grinding marks from sharpening and, upon use, a new set of unique random nicks now distinguish that blade from its prior characteristics as well as from other blades. A study of two paper cutting machines and processes at a large paper company was made to determine if more than one pad can result inidentical edge features on each of the four sides. The process each machine uses to cut paper stock, the edge characteristics which result from the guillotine blade, and the likelihood of duplicate features are discussed. In addition, a method of photographing the microscopic features which remain on the edges of cut paper stock is discussed and illustrated. This information should assist the document examiner during comparisons of individual pieces of paper for the purpose of confirming common origin.