How to blend the putty used in ready mixed paint car paint?

The preparation of car paint putty is as follows: mastic: cooked gypsum powder (or white powder) is the main base material. Put the gypsum powder into a bowl or glass plate, first add a proper amount of water, fully stir to make the gypsum powder swell, then add thick leather glue, and add red soil, floor yellow, ink and other pigments according to the color of furniture to fully prepare thick porridge. For example, if the putty is big white powder, it is enough to add leather glue to the big white powder at one time.