Q. Can I use my acrylic and watercolor brushes for painting with water-soluble oils?
Deer Park, NY
A. You may use your brushes any way you choose if you get the results you want. But your brushes will generally work better and last longer if you use them with the medium for which they were designed and give them lots of TLC.
Over the years, brushes have been fine-tuned by manufacturers in response to artists requirements, and each one is made for a specific purpose. Their fibersnatural hair, synthetics or a mixture of the twohave qualities that respond to their use in very particular ways. As a result, their versatility has some limitations. The two areas that most notably affect these limitations are the viscosity of the paint and the solvent youre using with the paint.
If you use paints thickly, as in impasto, bristle brushes will be the most useful because theyre the stiffest. So if youre using your water-soluble oils thickly, I wouldnt recommend using your soft-hair watercolor brushes. Your acrylic brushes, however, are acceptable in this case if theyre synthetic or relatively stiff-bristled.
If you plan to use your water-soluble oils more thinly, as in glazing, use soft-hair or synthetic brushes designed for oil painting. Although the soft-hair, short-handled brushes for watercolors may resemble those used for oils, theyre not the same. Watercolor brushes are designed to store and dispense a lot of liquid, making them difficult to control in dispensing thin layers, while those designed for oils (particularly the long-handled kind) generally have flatter shapes that glaze more easily.
Soft-hair watercolor brushes may give you problems with water-soluble oils when it comes to solvents, however. These brushes are typically cleaned with water, but water-soluble oils may leave behind a film of oil on the fibers of the brushes that water wont be able to remove. If you try to use a solvent appropriate to oil-based paints—namely turpentine or mineral spirits—on these brushes and then return to painting with acrylics or watercolors, your brushes may resist these water-based paints because of a solvent residue.
Ultimately, if youre really curious, the best way to understand the limitations of your brushes is to experiment with them. You may find some applications that give you unexpectedly satisfying results. But if you want longevity and consistency from your brushes, stick to the media they were designed for.