Two simple line tools to help you trace perfect abs.
I always had trouble drawing abs on bodies so I decided to experiment and made the simple tools. 


All you have to do is place the lines on the stomach, use mesh transformation, and trace over the lines using shadow and highlights on a separate layer. I made a video to show you how it works.

I did it really fast so I apologize if the abs are not to your liking. The first Abs tool is with an elongated third row of packs and the second one is more balanced.
Category 1