In Is it Fabricated?, document examination expert witness Ronald N. Morris writes on what material can be on a copy in addition to the material on the original. “Copies may include toner reproduction of scratches, trash, dirt, etc., found on the glass or drum.”
…b. Even if a number of these qualities and features are present in the copy, it cannot be concluded that the copied document contained an originally written signature. Document fabrication, complete with the addition of signatures extracted from other documents, is relative easy to accomplish.
c. Writing features found in the original document paper stock, such as indentations or indented outlines of letters and words, the disturbance of paper fibers due to mechanical abrasive erasure or the use of liquid solvents or eradicators, insertion of a number or letter using a different ink, etc., are not exactly reproduced during the copying process.
d. Embossing caused by heavy writing pressure on a soft writing surface.
e. There are a number of other characteristics, qualities, and features found on an original that are not accurately reproduced during the copying process.