As much fun s it is to work with cold wax and oils, perhaps you wish to work with traditional oil paints while keeping the "fat over lean" requirement nice and simple? If so, Gamblin Colors has a fairly easy way to do it. First, why would you want to work with traditional oils vs cold wax/oil? If you are a more representative artist, or wish to use brushes with more fluid paint with more control of edges of shapes and lines, then this might be a reason. Cold wax/oil is great for thicker mixtures with lots of texture. So, let's say you wish to work with oil paints without cold wax as the medium. What medium should you use to honor the "fat over lean" principle? Do you need to worry about all the different kinds of oils out there (walnut oil, safflower oil, linseed oil, etc) and thinners like turpentine? No!
According to Gamblin Colors, you can simple use a mixture of Galkyd:Gamsol 1:1. Here is what they have to say about this mixture for those who wish to work with traditional oils:
"One of the advantages of the 1:1 Galkyd:Gamsol mixture is that its oil (fat) content is very close to the paint out of the tube. So, one can add as little or as much to color, no matter where one is at in the painting process. The alkyd content equals fat in this equation. If one were using Galkyd straight, then it should be used sparingly (or thinned with Gamsol) in the early stages and then used more as the painting progresses." --Scott Gellatly
Wow! This is GREAT information! Thank you, Gamblin Colors