You can — but with important limits.
Oil paint can be used to add colour to encaustic medium, but you must use only a very small amount. The oil in tube paints is linseed or safflower oil, which is not compatible in large quantities with wax. Too much oil will prevent proper adhesion and cause the surface to remain tacky or even delaminate over time.
Health Concerns:
- Oil paints often contain oxidized linseed oil, resins, or other additives that can emit volatile compounds when warmed.
- Oil paints can contain toxic pigments. Avoid: paints containing cadmium, cobalt, lead, chromium, manganese, or nickel.
Tips:
- Use artist-grade oil paint (not student or water-mixable types).
- Add only a trace — about 5–10% oil paint to 90–95% encaustic medium.
- Blot excess oil from the paint on a paper towel before mixing it into the encaustic medium.
- Ensure good ventilation and proper temperature control.
For health and safety, this method is less ideal than using commercial encaustic paints. For best results, I recommend using ready-made encaustic paints (like R&F, Enkaustikos, or Kama).
When mixing oil paint with encaustic it is important to understand oil and wax relations see this Wax/Oil Ratio diagram from R&F.
There is a danger (the painting won’t be archival), in making a mixture where the amount of oil and the amount of wax are equal. Do not add more than 25% paint to 75% medium or you will end up with a wax that won’t harden.
