Making Decals
Whatever you print them on you will have to cover them somehow. Inkjet ink turns into a mess when it gets wet - I doubt it will survive glow fuel.
You could probably print on regular paper then just cut off all of the blank paper. You could put clear paint or covering over it to protect it. You could also try printing a mirror image on a transparency and turning over so that the ink is on the bottom. That would be really tough.