I have seen a few abdominoplasty "tummy tuck" scars where they are completely hidden under tattoos. Possible or camera trick?

I have occasional performs tummy tucks and lined up existing tattoos.  More often, women get a tattoo after a tummy tuck and more likely that is what happened in the cases you are talking about .

You should ask the PS who performs your TT the appropriate time to have a tattoo following the surgery.  In general, scarring is a produce of genetics. Some people are good scar formers and others are poorer scar formers. The scar will fade over a year’s time.Kenneth Hughes, MD, Board Certified Plastic SurgeonLos Angeles, CA