With learning about how paintings were made in centuries past, much attention is always paid to the how the studio is run, with apprentices doing the work of grinding oil into pigment, and to how difficult obtaining colors could be.
I am very interested in pigments, but that story seems to be missing the other half of the paint.
In contemporary painting, oil paint is mostly made with linseed oil. But what is linseed oil? It comes from flax right? What was done to flax seed in order to make linseed? The more I looked into this, the more elusive the answers seemed to be. Most literature I can find avoids the topic altogether, and older books still in print, have just brief descriptions of boiling it.
My wife then surprises me by giving me a present of a hand powered oil expeller. And so I began experimenting with extracting oil. But the oil has to be 'refined', but how would that be done without boiling?
So, after some communications with a few paint manufacturers, I felt a little more confident I was on the right track, and then discovered online someone else refining his own oils, with recipes on his website.
Turns out the process is pretty simple but strenuous.
Following these steps I have been making all the oil I use in the studio both to make my tubed paints, and as a medium to use while painting for the last several years, I feel that this process, along with other historical practices, have helped me bring my art to a higher, more personal level.
I am not an expert of much of the science behind how and why, but I am passionate about learning techniques and materials of a time when painters were not called artists but craftsmen.
Tad Spurgeons book is a great resource for info about the refining process of oil's, and a great book all around. Highly recommended!