Since tattoos are so mainstream and common now, they probably send the opposite signal today than they did in the past. When I meet people under 40 or so -without- tattoos, my first impression is they might be more interesting, trend-bucking, counterculture, free thinking, etc.

Obviously tattoo/no tattoo is a bad, low-signal way to size someone up, just pointing out the signal itself has phase-inverted from say 20 years ago.