When grinding the paint you use, black oil and powder pigments. These pigment are readily available at fine art store and industrial supplies. First we will be using a piece of marble and a pallet knife, Dip your clean knife into the black oil and retrieve just enough oil to fit on the surface of the knife. Clean the knife with a paper towel and dip the same knife into the pigment. (picture shows amount) You don't need much.
Put the pigment in the oil and carefully mash the powder with the knife.
Mix the two elements until they are the consistency of soft butter.
Transfer to your pallet. You are ready to paint.
After your paints are mixed (remember to only mix what you need because they
have no preservatives so by morning they will dry) you need to make medium. You do this by mixing equal parts of mastic varnish and black oil. Dip your clean knife into the black oil and then use a paper towel to wipe it clean. Put this on your stone. Dip your knife into the black oil and put this on the stone next to the mastic varnish and mix them together. They will gel immediately. Next time I'll talk about mastic varnish.