Since Tim seems to respect the opinion of David Purtell:
“Photocopies have several limitations. They do not reproduce all the fine details in handwriting needed in making an examination and comparison. At best, they do not produce as sharp an image as a properly produced photograph, and they lack tonal gradations, a result of the contrasting process of reproduction. In addition, it is possible to incorporate or insert changes and alterations into copies. A method frequently used is to paste together parts of documents to make one fraudulent document, which is then copied. If the first copy can pass inspection, it will be used; if not, it will be reworked to eliminate all signs of alteration. This amended copy is then recopied for the finished product. This is usually referred to as the "cut and paste" method. Document examiners only render a qualified or conditional opinion when working from copies. They stipulate that they have to examine the original before a definite opinion will be made.”