I'm using a Ceramic White oil paint by Holbine and no extra oil medium. The other colors are Old Holland Ultramarine, Old Holland Bt. Umber, Old Holland Indian Yellow Brown Lake Extra, Old Holland Gamboge, Daniel Smith Quinacridone Magenta, Rembrandt Chinese Vermilion, Grumbacher Thalo Blue and Liquitex Dioxazine. I must add some gloss to the pigments. I'll paint the next layer and the rest of the painting with an Gamblin Galkyd, an alkyd resin oil.
Alkyd resins are polyhydric alcohol with polybasic acid.
These alkyd modified resins are non yellowing and dry faster than natural oils. Liquin is another alkyd resin with added oil. Alkyds mix well with normal oil paints and speed drying. I love it . Alkyd oil has some of the same qualities as water based acrylics and some of the best qualities of oil.