get everything needed on a signed cheque.
A check is no good, most checks are now printed on paper with special lines that are supposed to become obvious after copying. A signed letter or even a mailing envelope would probably be better.
Actually for the purposes of fax you can trace the signature off the check and then photocopy the traced outline. If you use Mellonex film you can get a very good impression.
Also, scotch tape makes those pexky shadows disapear like magic. My dad uses it to make multiple versions of make-up math tests that trivially look like the origional in order to goad persons who were sick on test day so that they could get the answers from someone else into printing down those answers and getting less than random probability. (multiple choice)
When I used to do layout of artwork for a magazine we used to use white out to get rid of the shadow lines. There is a particularly good version available in the UK which comes in a red bottle with a flow cap on it. Much better than the crappy pot 'n brush system which is always going hard as the solvent evaporates. Phill PS: I hasten to add that my experience of fraud techniques comes from trying to stop them. PPS: In the days of electronic mail why do people need PS's?