Oil paint is mainly pigment, and drying oil, and at times a stabilizer. I think that an oil paint with some form of stabilizer makes a better paint. The oils are poppy, safflower, walnut, and linseed. Many artists use different oils, for different reasons. I generally prefer linseed oil. It is very durable, and has been used successfully for centuries. Safflower is very good at mitigating the yellowing effects seen with linseed oil. For lack of a better explanation, I love the smell of linseed oil, and when it comes to making paint, the cold pressed version is excellent. Cold pressed linseed oil wets pigments better than alkali-refined linseed oil. When made in factories, this is no concern, but I have found it much more effective when making my own paint.
Several years ago I was on vacation in Arizona, and visited Sedona. It was red! A beautiful iron oxide red, everywhere. Immediately I thought that the sand would make a very nice color in paint, so I collected some in a plastic bag.
I took this material, and cleaned it several times to remove organic material. I then baked it to dry, and although it was already very fine in particle size, I ground it down much further, to the texture of my other dry pigments. When sufficiently ground, I added cold pressed linseed oil, and ground the pigments into the oil. Somewhat gritty at first, they did break down into even smaller particles, with a great deal of effort, and time. The thing that was most interesting is that as the particles became smaller, the color of the paint darkened. In the end, it was very dark, and didn't appear red at all. More of a burnt umber color, but with much different working properties. When mixed with white, it does have a red hue, but there is a notable shift to yellow. In mixing this color with venetian red, and titanium white, it produced a flesh tint that was so right on, with relative ease, that when I wiped the paint laden brush on my hand, the color was indistinguishable from the local skin color. When mixed with ultramarine blue deep, a wonderful black results, and I have found this black to be very close in hue, and working properties to the actual ivory black, made from actual ivory.
Considering the amount of effort and time that went into this, I don't think I will make a huge amount, but it was a good experience, in keeping with the craft. The amount that I produced after about 8 hours of work, was approximately 35ml. A similar amount to a single tube of paint, bought in the store.
The remarkable thing about this paint, is that although enmasse, it resembles burnt umber, or any number of mixes, the working properties create a much more subtle effect. It is not overwhelming in the least, nor is it gritty. I would add that as a stabilizer, I used a very small amount of amber varnish that I made earlier this year (about the size of a lima bean). It immediately congealed the paint, and made a wonderful texture. This truly is an earth color. Please excuse the pile depicted, as it does resemble another less than desireable substance.