Going back to the Warhammer thing, this was what I was thinking about: http://bitzbarn.com/oscommerce/catal...icleDecals.jpg

That being said, I don't know how it will stand the test of time and wearing out in the field but it's something to start with/consider.

As for engraving, I guess one of those sports trophy/engraving stores could do it for you. You should have your "engraving" reference pic done in high res jpeg, svg, psd, postscript, or a similar "vector" image that is easily scalable and high resolution. Also it's probably best if you tell them it's for a RAP4 paintball gun or something if they ask.

Also I know this may sound really retarded but I'd actually consider putting a "Type R", "Type S", and "Safe" as my trigger group on a gun (corresponding to Auto, Semi, and Safe respectively).

If you're worried about rubbing the decal off, there's some tricks of the trade that I can hook you up with.

I have worked fairly extensively with plastic models. One way to coat your decals is to airbrush a layer or two of Future Floor Polish over top of it, to seal the decal.

Nice ;)