Caring for Artists' Brushes

When you read about caring for equipment, one of the most confusing seems to be what to do with those expensive brushes. Long ago I learned to wipe away excess paint, rinse carefully in mineral spirits and dry, wash in lukewarm water with gentle soap and then condition my natural fiber brushes with conditioning gel. Synthetic brushes require less--wipe, rinse, wash. One of the more controversial recommendations that one reads on social media is storing brushes in oil. Many swear by the use of an oil to not only store brushes but to clean them too. Brushes are quite varied, though, both in materials and in manufacture, which makes for serious confusion. (This post refers only to oil painting. Watercolor and water media brushes obviously shouldn't be cleaned with or stored in oil.) 

Hog Bristle Brushes (Four Shapes)

A quick review of brush types is in order. First, there are brushes made with natural hair or fibers. Among this enormous group are hog bristle brushes and natural hair brushes (sable, for example). While I've no data, one suspects that these are the kinds of brushes in widest use by serious painters. The second group of brushes are made with synthetic fibers like nylon (Golden Taklon is an example). Caring for these different kinds of hair and fibers is necessarily going to be different--one method doesn't necessarily fit all.

There has been wide discussion online about how best to care for oil painting brushes, with a loud contingent recommending cleaning them in an oil and then storing them in oil as well. This particular regime and habit grew out of sign painting and has been adapted by some to care for their oil brushes. However, it seems to me that at least some of those folks may not realize that the method may not be the best for all of their expensive brushes.

Several Sizes of Round Sable Brushes

Considering that cleaning and storing brushes is a critical skill for oil painters, it seemed reasonable to ask an experienced sign painter who is also an oil painter about the process. I interviewed my friend Richard Bingham, who operates Idaho Graphics for this post.

Q. Before we get to cleaning oil brushes, can you discuss the types of brushes used by sign painters and how they were kept?
RB: Sure. Hog-bristle cutters, flats, and strokes were segregated by color groups. So there were separate sets for red, yellow, blue, etc. Each was wrapped in brown paper in way to preserve the shape and kept in cans of mineral spirits between uses. They were never washed in solvents and soap and water. Soft hair brushes were kept with their fibers in a non-drying oil.

Q:  Why do sign painters use an oil to clean and store their brushes?
RB: Sign painters use (or used--many signs are no longer hand painted) primarily soft brushes for lettering, fitches, quills with brown or grey hair, camel, ox, and other natural hair, and of course they were using mostly alkyd enamels that dried rapidly, were of a consistent viscosity, and generally controlled it with "hot" solvents like turpentine, mineral spirits, automotive thinners, Penetrol, and other rather nasty stuff. Throw into the mix that brushes were used all day every day and cleaning brushes and keeping them soft in suitable oil made sense.

Q: How did they clean brushes?
RB: As is recommended for any brush, thorough cleaning well into the heel and hafting of hairs [i.e. the ferrule] is especially important. Using a light oil that can penetrate well can eliminate paint residues when properly worked into the heel of a brush. Of course, drying oils are "out" since they would ultimately be counterproductive if the brushes were put aside for any length of time.

Q. Okay, so if drying oils aren't good for brush storage, what oil can be used? 
RB: Sign painters have been known to use motor oil, which is a poor choice, castor oil (which, amazingly, behaves as a drying oil given enough time), lecithin (a generic term for a group of fatty compounds found in plants and animals and a component of many lettering enamels), and neatsfoot oil. Of course, the possibility of contaminating one's paint with a problematic oil is a consideration.

Q. You're both an oil painter and sign painter. What do you recommend for cleaning and storing oil painters' brushes?
RB: Soft hair brushes may profit from the sign shop method--storing in a non-drying oil--but hog bristle, being a hollow-shaft hair, eventually becomes oil-saturated and "logy," losing it's stiffer handling and defeating the purpose of the type of brush.

So in summary, if you're interested in reducing your use of solvents, perhaps storing some of your brushes in oil would be useful. However:

• Do not store hog bristle brushes in oil unless you don't care if they become soft and feel rather mushy. Instead, wipe out excess paint, wash them in warm (not hot) water, rinse and store with the fibers upright. If you're careful, you can manage this without solvents.
• Synthetic fiber brushes like nylon can be treated the same as bristle brushes--no solvents, mostly--and do not need an oil storage bath.
• Storing soft brushes--sables, and so on--with the hairs in oil may be useful if you don't use inappropriate kinds of oils. 

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Previous Posts on Brushes:
Brushes Part 3 Care and Maintenance
Brushes Part 2
Brushes Part 1