I used to help a guy fiberglass surfboards and all of the decals that those guys use are not stickers or vinyl, they use rice paper and print their design on the paper, then when they lay resin over top of the rice paper all the resin gets absorbed into the paper and just leaves the printed design visible. The paper is NOT clear when you print on it, but it is VERY permeable so when you lay fiber glass resin or clear coat over top it just becomes part of that layer and is clear. Its a great way to do decals or custom designs on the cheap.
HEREis a link to a site I looked up with paper you can buy (Im sure you can find it cheaper than this). I know there are also digital printers who will print on rice paper for you but they may have a minimum on how many they will run for you. It may seem unconventional but Im telling you, this stuff works great.
cody