I gave up on printing labels. Instead, I bought permanent markers (gold and blue). I don't write out the entire flavor; instead, I use abbreviations so I'll know what they are. Then I put a tiny piece of clear tape over my writing so it doesn't rub off.
By the way, I write near the bottom of the cartomizer. In the beginning, I was writing near the top, but had trouble getting the cone on when I use my CigEasy Elegant.