(Excerpts from ART HARDWARE: The Definitive Guide to Artists’ Materials, by Steven Saitzyk © 1987)
There are four things that will end the life of a brush-wear, dried paint, mildew, and moths. Although there is little that can be done about wear, damage from dried paint, mildew, and moths can be easily avoided by proper cleaning, proper drying, and proper storage.
Thorough cleaning involves removing material that gets caught in the scales of the hairs or that builds up near the ferrule. Material trapped in these locations prevents the brush from returning to its ideal shape.
Watercolor Brushes, both Western and Oriental, and calligraphy brushes made with natural hair, are best cleaned by rinsing with room-temperature waternever use hot water on natural hair brushes-when watercolors or nonwaterproof inks have been used. This preserves the natural oils in the hairs that protect them from becoming dry and brittle. However, since dyes are sometimes used, which stain the hairs and tend to dry out the brush and affect successive uses of other colors, and because it is difficult to be patient for all necessary rinsings, a cleaning aid may be used.
Do not clean watercolor brushes with anything that you would not be willing to use on your own hair. You would not use liquid dishwashing detergent or paint thinner to wash your hair. Neither should these be used on expensive brushes that could last for decades if properly cared for. True soaps such as Ivory soap do far less damage than chemical detergents and are recommended for cleaning fine brushes. Some of the new cake brush cleaners (the Masters Brush Cleaner and Preserver by B & J Company and Brush Soap by Grumbacher) that have recently come on the market function like hair shampoos. They contain mild chemical detergents combined with such conditioners as natural oils like lanolin, which replace what is removed in cleaning. Some artists use their own shampoo and conditioner on their brushes. This would seem to be an acceptable alternative as long as the brush hairs are not made too oily from the conditioner, in which case they could lose their natural absorbency.
After a brush has been cleaned it should be reshaped and allowed to air dry thoroughly before being stored. The best way to allow a brush to dry, particularly a large brush, is to hang it with the tip down. This will help prevent moisture from being trapped in the ferrule, which would cause the brush to rot.
Acrylic Brushes, or those used with vinyl paints, must be periodically rinsed clean while you are working, because the paint that is trapped near the ferrule is drying while you are working with the tip. Small amounts of paint buildup in this area will not wash out once dry and will eventually render the brush useless. The only way to prevent this is to rinse the brush thoroughly every fifteen to twenty minutes with warm water. When finished, cleanup can be accomplished easily with soap and warm water, or with any of the new commercial brush cleaners.
If acrylic or vinyl paint has dried in a brush it can be removed with acetone. Acetone will, however, rob a brush of a great deal of its life, if not destroy it. (It should be noted that nylon brushes tend to dissolve in acetone.) Acetone is a hazardous substance, which can be absorbed through the skin, and frequent use may reduce your life expectancy as well. Manufacturers of the new artists’ brush cleaners claim that they can remove some dried acrylic paint. There are also artists’ brush conditioners, such as Silicoil, which can help recondition a brush with dry and brittle hair.
Oil Brushes can be cleaned easily without the use of such solvents as turpentine, petroleum distillate, or paint thinner. (Paint thinner should always be avoided for cleaning brushes.) Plain soap and water, or an artists’ brush cleaner, work extremely well after the brush has been wiped free of excess paint. But this procedure is not workable when it’s necessary to clean a brush quickly so that it can be loaded with a different color and continue to be used. In this case, the brush will have to be rinsed with thinner, but it should not be left sitting in thinner.
I recommend that a jar of solvent, such as turpentine, be set up with a coil in the bottom of the jar. This provides a nonabrasive surface to scrub the brush while rinsing it with thinner. The jar should have a cover to protect against evaporation when not in use. This will allow the rinsing of the brush between color changes as well as before final cleaning with soap and water. When it is time for cleanup, the brush is first wiped clean of excess paint, then quickly rinsed in the jar of solvent, and finally washed and allowed to air dry. Periodically, a brush conditioner may be used to restore performance. This method keeps the exposure to thinners at a minimum.
As for brushes with dried oil paint, if an artists’ brush cleaner is not successful, it is time to consider a new brush and better work habits.
Synthetic Filament Brushes
Synthetic Filament Brushes can easily stand repeated exposure to solvents such as turpentine, petroleum distillate, and most paint thinners. Solvents such as acetone, however, will dissolve nylon filaments. Synthetic brushes that have lost their shape, perhaps because the weight of the brush was left resting on the tip, may be restored by placing the brush in water that is hot, but just below the boiling point.
After a brush has been cleaned, reshaped, and air-dried, it has to be protected. All brushes, whether made from natural hair or synthetic filament, have to be protected against mechanical pressure. Never store a brush resting on the tip, or in a container so small that the tip is pushed against one of the sides. The hairs or filaments will take on a distorted shape that is difficult to undo. Natural hair brushes can sometimes be reshaped by giving them the equivalent of a shampoo and set. This involves rinsing the tip of the brush in warm water and attempting to reshape it. It may be necessary to repeat this effort several times. Sometimes it is helpful to dip the brush into a solution of gum arabic after the warm water treatment to aid in reshaping. Synthetic brushes may be reshaped with hot water.
Natural hair brushes, especially expensive watercolor brushes, have to be protected from moths, which may lay their eggs on the hairs, which will be food of the larvae when they hatch. Never place a brush in a plastic bag and put it in the dark. This may keep the moths off the brush, but you will be providing a fertile ground for mildew and rot.
I recommend using a Japanese brush holder for storage. This resembles a bamboo placemat with a string attached at one end. Brushes are simply rolled into the mat, which permits the circulation of air and protects the brushes from moths. If you are storing large brushes in a Japanese brush holder, it is a good precaution to wrap a cotton cloth around the holder to prevent insects from crawling into the partially open end. Moth balls, or flakes, provide extra protection and are particularly important when storing brushes in drawers.
These storage procedures are not necessary if the brushes are used every day; then they may simply be placed upright in a jar when entirely dry. Whenever they are not to be used for several days, however, it is best to store them away using one of the methods described.