Damar resin has long been the hardener of choice to combine with beeswax in encaustic medium recipes. Because of its high melting point, it aids in making a more robust painting than pure beeswax and allows for vigorous buffing over a curing period to bring the work to a shine. A downside can be that due to its organic nature, damar has been known to yellow over time. This may happen in varying degrees over months, years or decades, though artists who combine pigments with their medium will typically never notice this. For those who rely on many clear layers, it could become an issue. Most pieces seem to remain as the day they are painted, but if you do experience yellowing, or simply want a whiter medium, there is a solution. I recently took a deep dive into the use of an alternative to damar, castor wax.
Australians pioneered the use of castor wax as a replacement in their encaustic medium years ago in response to the exorbitant price of importing damar. The wax is derived in a roundabout way from castor beans, available domestically and much less expensive.
After many conversations and e-mails with artists using this combination for years, I embarked upon testing. I can’t yet speak to its longevity in my own experience, but those I spoke with assured me that time has had no effect on their pieces. Some had art on hand created years ago using each recipe (castor and damar) and there were no noticeable differences. They all confirmed that no yellowing had occurred.
Using Castor Wax in Encaustic Medium
My major impression of using castor wax is that it is a joy to work with.
Following are my findings. In all cases, I am comparing caster to damar as combined with beeswax to make encaustic medium.
- It makes a whiter medium, not clearer, just whiter. See photo of 4 layers of each painted onto bare birch.
- It seems to flow smoother and thinner off the brush. Damar medium has more body and viscosity.
- It is more slick and less sticky when cooled. If you get it on your hands it’s not as gooey as damar, nor does it roll into a ball as easily. When doing transfers the paper tends to slide around the wax more upon initial placement.
- Castor has a lower melting temperature than damar, but still higher than pure beeswax. This should be of no concern to the final artwork as Australians have used it with great success for years in their warm climate.
- Anecdotal reports indicate it hardens up well over time.
- You can use the same ratios for each. Most I spoke with use 8:1, but Langridge Artist Colours in Australia uses 6:1 in their commercial formula. I preferred 7:1.
- Castor makes a more brittle medium when comparing similar ratios, but nothing that would affect my work on a rigid support.
- It appears to buff to a shinier finish than damar.
- No straining is required as there are no organic bits embedded in it.
- Castor performed well in my freezer tests, adhering to bare birch panel, encaustic gesso (R&F) and chalk paint (Cottage Paint brand).
All of that said, I have come up with a formula that works well for my process that actually includes a combination of both damar and castor. I expect this will change with each batch as I hone in further, but I can’t really see myself ever going back to full on damar in my medium. Don’t be afraid to experiment with small batches to discover the specific formulation that allows you to bring your vision to life. A digital scale is your friend.
Castor wax flakes are widely available in stores carrying botanical ingredients for those making home balms and creams.
If you’re looking to purchase encaustic supplies, please support local small businesses when possible. You can purchase encaustic medium made with Castor wax from Karen Brown.
Have you tried Castor wax? Please add a comment below and let me know what you think.