Brush care for oil painters

December 17, 2023

I spend hundreds of dollars a year on brushes and many hours at night washing the oil paint out of them as my family slumbers. I’ve decided to turn to the experts to see if I am doing the right things.

Brush use: Be gentle and do not let paint go up to the ferrule (metal part). (That doesn’t work for me; the paint goes right up my hand sometimes.) Because I mistreat them, they go all “wire-haired terrier” on me when I prefer a chisel-sharp edge.

Segregate: Don’t mix acrylic brushes with your oil brushes. Acrylic paint contains surfactants, making oil paint more sensitive to water and affecting its performance.

Resting brushes: Wipe off oil paint onto a paper towel and rest the brushes in oil during, or between, painting sessions. Use the same kind of oil that is in your paint to avoid adulteration with slower-drying or never-drying oils. I use linseed oil, but walnut oil is also recommended. Use a painter’s tray or something similar, so they are not tip-down and distorting the shape of the brushes.

Solvents: Some people never clean their brushes. They just wipe off the paint and keep them in oil. I tend to wash mine when I’ve finished a painting. Other people may swirl the brushes in turpenoid or Gamsol before washing. Solvents are not necessary for keeping your brushes clean, however. If you use them, don’t immerse your brushes to the ferrule because it can dissolve the glue that holds the hairs together. Solvents can also damage the hairs of your brushes.

Oil cleans oil: You can use cheap vegetable oil for washing the brushes, so long as they are thoroughly washed with soap before reusing. George O’Hanlon, co-founder of the Natural Pigments brand, recommends vegetable oil, but warns supermarket oils such as canola, peanut and corn are non-drying. They must be completely removed in the washing process. Many supermarket oils also contain Vitamin E, an antioxidant that can hamper the drying of oil paint.

Soap: Use a gentle, unscented vegetable oil soap (such as olive oil or Castile) to wash the brushes in lukewarm water. George O’Hanlon recommends using a toothbrush to stroke stubborn paint from the brush (ferrule to tip). If the ferrule is clogged with paint, the brushes will splay. Conditioning is not required for brushes washed in oil and soap.

Substances to avoid:

Handwashing soaps often have abrasive materials, such as walnut particles, to aid cleaning. These particulates may get into your paint and be less than gentle on your brush.
Dishwashing liquid contains surfactants and alcohol. Residue in the brush will affect the water sensitivity of the paint film and contribute to its degradation.
Baby oil is a non-drying mineral oil and contains vitamin E, which is an antioxidant and can slow paint drying times.
Clove oil slows down the drying time of paint and is expensive.

(Source: Painting Best Practices Facebook group)

Reshape: Wrap damp brushes in toilet paper. For the flat ones, I also use a clothes peg to fasten folded cardboard over the top (go to my website for a video of the process). If the brushes get out of control, I first dip them in gum Arabic. When used again, flick them with your thumbnail to separate the hairs and disperse the gum Arabic dust. I find that this prolongs the sharpness of the edge or point for a little while. Some people reshape using Vaseline, but art educator Virgil Elliott does not recommend this. Vaseline is a non-drying petroleum oil you don’t want in your oil paint.