Collodion is a classic product for creation of simulated scars (also known as Scarring Material).
Apply one coat onto the skin.
Press the skin together to form a fold.
The Collodion will form a temporary line in the skin that resembles a scar.
The artificial scar can be coloured with a Greasepaint.
Remove with Collodion Remover and moisturise the skin after removal.