Medical tattooing can often be a great way to make scars, stretch marks and other skin discolorations less noticeable. Scar tissue is different to work with than regular skin so it’s important to have this work done by a medical tattoo artist and not a regular tattoo artist. You must be at least 18 years old. Expect that the tattooed areas will fade with time and occasionally need touching up. Sun exposure can cause faster fading.