Understanding and Preventing the Yellowing of Oil Paints

Modern oil paintings, while vibrant and long-lasting, have challenges. From yellowing over time to increased water sensitivity, these issues can frustrate artists. This blog delves into recent research to offer practical advice on mitigating the yellowing of oil paints, helping artists ensure their works stand the test of time.

The Phenomenon of Yellowing of Oil Paints

Yellowing is common in oil paints, particularly those based on linseed oil. This phenomenon occurs due to the oxidation and polymerization of the oil, leading to a yellowish tint. The study by Mallégol, Lemaire, and Gardette (2001) provides a comprehensive analysis of the factors contributing to this issue.

Key Findings on Yellowing of Oil Paints

Recent research published in Just Paint reveals new insights into the yellowing process, particularly with Titanium White paint. Contrary to the belief that simple blends of pigment and oil are always the best, the study found that paints made with Titanium White and alkali-refined linseed oil yellowed the most. This yellowing was exacerbated when the paint was applied in thicker layers, resulting in significant oil separation during drying.

The study showed that adding barium sulfate or calcium carbonate to the paint mix resulted in less yellowing and reduced oil exuding to the surface or out the sides. This finding indicates a strong correlation between yellowing and the paint’s ability to fully bind and hold onto the oil, preventing it from seeping out.

Adding beeswax as a stabilizer significantly whitened the paint, especially in thick applications. While the addition of beeswax may have prevented oil medium skins or oil from rising to the top of the paint film, thereby reducing yellowing, it also makes the paint more susceptible to solvents used during cleaning and varnishing. Adding driers further reduced yellowing, contrary to the common belief that driers increase yellowing.

Mitigating Yellowing of Oil Paints

To minimize yellowing, artists can take several steps: