This Neil Armstrong signed "cut" was sent to me recently for review. The moment I took it from the envelope my radar went off because it was not a 3x5 index card, but printer photo type paper cut to the shape of a 3x5 card.
I also immediately knew something was amiss because the signature seemed too "flat." It was on the surface of the paper, but there was no ink streaking.
Here is what it looked like under magnification:
So, it was a high quality inkjet print. This "signature" is composed of dots, not ink from a pen.
I have seen a number of these printed signatures and it appears to be a growing problem. Often they are matted in a display -- at arm's length and under glass they can be more deceptive. As always, caveat emptor!