Prevention Measures
Firstly, to limit a criminal’s ability to steal a check, make sure to place it into a locked postal box. Never leave it on a desk, in the outgoing mail folder or a box anyone can access.
There are a number of features to prevent checks from being scanned. Printed features like high-resolution borders, micro printing, void pantographs and complicated, colored or prismatic backgrounds are good. But any printed feature may be copied with high-quality optical devices. A high-resolution scanner and top-of-the-line printer may be able to passably reproduce these features, though not without difficulty. Non-printed features like UV inks (inks that glow under blacklights), UV fibers, holograms, watermarks (both true and artificial) and thermochromatic inks are highly effective. Scanners and copiers cannot reproduce these features at all. A forger would need expertise, time and equipment to adequately reproduce such features. As Abagnale explained, most criminals are not interested in investing time and effort to forge a complicated document; they will likely move on to an easier target. True watermarks are unforgeable as they are physically embedded in the paper. The same goes for UV fibers. The combination of watermarks and thermochomatic inks is an especially good security combination. Both are easy-to-verify, hard-to-reproduce, features that cannot be optically copied.