Hi Sunny,
These are the details on the paint,
Gain primer paint >> no need for specific gain >> we typically provide a grey close to 0.35
Gain top paint >> 0.4
Purpose of Primer Paint >> A primer is a first layer coating put on screen before applying the Top Paint. Priming ensures better adhesion of the top paint to the surface, increases durability of the top paint and provides additional protection to the screen being painted.
Kind Regards
Sammy