It is these individual characteristics that allow for the identification of an object to the exclusion of all others of its general type. These defects in the type face are revealed in a number of ways. The letter can be displaced horizontally or vertically. Little clumps of plastic can adhere to the type key during manufacture and are made permanent by the coating process. As wear and tear increases, the defects become more exaggerated.
Ribbons are a major evidentiary component.
It is possible to read a ribbon to see what it has been used to type. Photocopiers and Laser Printers. Photocopiers and laser printers use the same type of process to print a page. With a photocopier, the original document is placed on the glass platen. The document is then exposed by use of reflected light to a drum that is covered with a photosensitive material.