Examples: Just because you have a scar doesn't mean you can't be tattooed or pierced. However, it does require extra care. Piercings are usually done near, but not over, old scar tissue to reduce the risk of further damage. Tattoos can be done over scarring, but the skin in a scarred area tends to not hold the ink as well. It takes extra patience and skill on the part of the artist to pull it off without it resulting in poor tattoo.

Elsewhere on the Web:

What's in a Scar?
More information on how scars are formed and how they can be treated.