You'd have to skin yourself up pretty good to ruin a tat. Almost to the point exposing fatty tissue. I don't think you're going to do that on a climb. If you lay over your bike and slide 100 feet maybe, but not from jamming in OW's. I climbed carniverous in a sleeveless shirt and I've got pretty good sized tat's covering both arms and the ensuing rock rash did absolutely no harm to the work.
Sounds good. Some one asked me and I had no idea, not having any kind of tat. I thought if the sun could fade it, maybe getting it scraped might fade it or make it blotchy.
I have to say I've used various body parts to smear or hook while climbing i.e. chin, forehead, knees, butt, etc. but the nipple smear was something to see. This guy was in a full body crux on a highballer and was essentially smearing with his entire body. Alas, the feet cut and his nipple just could not support his weight. It could have been the first documented nipple-flapper.
You people know just how to make me cringe! 
