They make a paper that you can get online or at some hobby shops that you can make your own decals & print with your printer. I haven't used it on an E-cig, but I made a pretty cool one for a guitar that I built. I think that's my favorite part of the guitarWhat about the decals available online for plastic models? Sometimes you see some really cool ones on the warplane models... should be able to find some quite manly ones.
Tryp