A silhouette matcap, this is very useful while sculpting with the Move or Snake hook brush in orthographic view to define the silhouette. It can also be used in a top down view camera to check the readability of a game character and his weapon for a MOBA game for example.
An example where this matcap is very useful with the Dota heroes: Steam Support :: Dota 2 Workshop - Character Art Guide
Download: https://drive.google.com/file/d/19cYjk6xbHcktPuV-hBg8DAdgwuSEMTXG/view?usp=sharing