Such a mixture is called a coupor primer.

In the third container in two liters of water, soap is dissolved, after which the olifa is poured into the resulting solution with a thin stream. As a result, an emulsion is formed, into which a solution of copper sulfate is added. At the final stage of the preparation of the primer for the fireplace, chalk is added and the volume of the solution is up to ten liters. Such a mixture is called a coupor primer. It has a greenish tint and for better quality is passed through a small sieve. It can be stored for a long time, for this it is placed in a cool dark place.