This is a demonstration of how to make a wax paste using beeswax, borax, and water. It makes a creamy medium that can be mixed into oil and casein paints to change their behavior.
In this photo you see a bag of bleached white beeswax pellets and a box of borax powder. In the jar is the end result of the combination of these two ingredients heated in a little bit of distilled water.
Process of making beeswax paste:
1> 4 ounces of beeswax pellets (measured by weight)
2> 4 teaspoons borax powder
3> 4 tablespoons distilled water
Yields @ 4 ounces beeswax paste
Melt the wax in a jar with a double boiler at 160° F, or in this case I used a baby bottle warmer.
In a separate jar combine the borax and water and heat that to 160° F also.
Slowly pour the diluted borax into the melted wax while stirring vigorously.
Let this cool to room temperature before sealing the jar (or else water may condense inside.)
The melted wax will turn an opaque white almost instantly when you add the borax. It will stay this color and never harden inside the jar. This chemical reaction, by the way, is referred to as saponification. The softened wax will act as a sort of emulsifier with oil and the water content of the paste. I’ve had my paste mixtures last for many months this way and possibly indefinitely, although; I’ve seen recommendations to add a preservative just in case.
Okay, by now you may be thinking that this is all very interesting, but what’s the use of it? Well, in one example, you may have come across some oil paints that are a bit too stiff to squeeze out of the tube, and do not have that common “buttery” feel that most paints have. You could either dilute the paint with an appropriate solvent, or add more oil. Those methods work fine for some uses, but they will make the paint either leaner or fatter, which is not necessarily desirable for your base paint. If you mix in this wax paste you can make the stiff paints more buttery without making them diluted or more oily.
For example, this tube of Grumbacher brand cobalt blue oil paint is so stiff in the tube that I’m afraid I might bust the seams squeezing it out. When mixed with a small amount of the wax paste it becomes easier to use.
Notice how the mixture at first looks much brighter. In this image you can see a small swatch of the paste by itself on the grey paper. Next to that is a swatch of the cobalt blue paint without the paste, and next to that a swatch of the two mixed together. At first the paint looks brighter and more saturated, but a few minutes later it has returned to the paint’s original shade. So after you’ve mixed this on your palette just let it sit there for a few minutes before using it. After this mixture has been exposed to the air for awhile it will start to stiffen up, so you’ll need to refresh it with more paint and paste.
Another interesting use of this paste is to combine it with caseins. It can increase the volume of the paint in a manner you couldn’t safely achieve with paint alone. It also has an interesting texture that works well for representing rough stones and the like. Here’s a detail of a painting I made using casein and wax. I hope you can see some of the texture in the darker area that was applied with a paint knife.
Other combinations to try are the additions of an oil like linseed into the paste and/or resins like damar. The oil will make the paste creamier and damar will make for a shorter stroke and improve adhesion. Shellac is another item that can be mixed into the paste and behaves like damar. Turpentine or mineral spirits can also be used in place of borax, but I’ve found that after a short while the wax returns to its hardened state. You could add those solvents to the wax paste made with borax, but there’s no particular reason to.