Hi
Take a look at my backpiece I had a number of fine scars (razor type) especially towards lower middle after a car accident (slivers of glass).
The main thing is if they are thin and well healed (over 12 months) they usually cover up well. if they are ragged tears, burns or skin graphs then the pigment has a strong chance of not taking well as the pockets of pigment have a harder time holding in scar tissue as fresh scar tissue needs to grow over the old.
In most cases of the thousands of pics I have seen the majority of ink has been able to cover ‘cutting’.
Take care
Matthew