It’s important to show the tattooist if you plan on getting a tattoo to hide an old scar.

Ideally the scar should be fairly dated and not be result of an important physical trauma. Usually scars within 6 months (wounds, cuts, etc) are too early to be tattooed on because tissue takes a while to heal and some tattoo artists don’t know how well the ink will hold.

In short the answer is that the ink could or could not hold well depending on how large your scar is. But if it’s fairly thin or small, and they don’t happen to be burn scars it shouldn’t be a problem.

Ask your friendly neighbourhood tattooist!
(or if you’d like to show/tell me more about your scars off anon I’ll gladly help you privately)