I know this is somewhat offtopic, but I'm really not sure where else to ask:
I've got an idea for (mildly) improving check security. Something similar has been done in the past, but that was decades ago and I know mechanical, printing, and usage rules for checks have been tightened in some ways since then; my idea may still be workable or it may not. I don't think it would be any more problematic than folding the check, but I'd really like to review the official definition of what is and isn't an acceptable check by policy before I start empirically testing whether the banking system will accept this idea in practice.
So: Where can I find a description of just how much a check can be "folded, spindled, or mutilated" before a bank should be expected to reject it?
Just in case anyone is wondering what the idea was... "Check writing machines" used to be common in businesses, which used various mechanisms to discourage alteration of the check. Some used a multicolored ribbon, some perforated the check in a pattern that told folks it was supposed to be a machine-printed check, and some embossed the printing. There was a home version which basically embossed a pattern over the value, with the idea that trying to rewrite the check would crush part of the pattern flat and provide evidence of tampering. I was wondering whether embossed checks would still be accepted, and what the limits would be.