Tattoos on reptile skin?

[ohmygoat]

So, basically I'm trying to create a race of reptile people,and am hung up on one small thing: would it be possible for them to get tattoos? If you can even get visible tattoos on scales, would it last if they shed their skin yearly?

The setting, while in a different world, has technology close enough to what we have today. At least, for tattooing.

I've spent the last week researching skin layers, tattoos, and scales, but haven't been able to put anything together.