by Jane Sutherland
The particular characteristics of the variety of artists’ brushes make them more or less appropriate for certain media and methods of application, so it is important to understand what each type can offer, as well as what kind of mark you want to produce. Short-handled brushes are generally used for watercolor, gouache, and tempera; and long-handled brushes for oil and acrylic.
First, brushes are categorized by their shapes: flats, brights, rounds, filberts, mops, and fans. Flat brushes have an oblong section of medium length hair that ends in a straight edge and has square corners. They come in two types: The longer ones are called flats, and the shorter are called brights. Flats and brights are great for bold, alla prima styles such as plein air painting because they are so versatile. A long-haired flat is sometimes called a one-stroke brush. You can make angular marks with the side of the hairs or with the tip, lay down long, broad strokes using the flat of the brush, or create a neat outline.
Rounds are most like the brushes used in the 19th century. As their name indicates, they have a circular ferrule. The pointed, fair amount of brush hair in a round makes it a good choice for small areas of detail.
A filbert is fuller than a flat and has rounded corners. Filberts are basically a flat and a round rolled into one. The sides of the brush can be used for a thin stroke, and across the width, a broad line.
Generally used like a wash brush, mops are large with a dome-shaped tip. Fan brushes, a blending tool, are named for their flat, thin head, with the hairs spread into a semicircular shape that resembles a fan. With the feathery edge you can coax paint into place after it has been applied.
The other important distinction between brushes is hair type. There are two simple categories: hard and soft. Hard, or stiff, brushes are better suited for thick paints, such as oil, because they hold more color and stand up under rough usage – scumbling or stippling, for example. Stiff brushes – such as bristle, badger, or fitch – are very good for covering large areas and for deliberate brush marks. White bristle brushes are the best bristles for oil painting. To make quality bristle brushes, the hairs are sorted into batches of uniform size so that the tips can be left untrimmed yet still make an even tip. They are strong, springy, and have a natural curve, which should arch in toward the center of the brush. Upon close inspection, you can tell if the bristles have been trimmed because, at its tip, natural untrimmed hair has a little branch that resembles a split end but is really a tiny sprouting of hair, in the same shape as spread-out tree branches.
Although soft-hair brushes are generally recommended for use with fluid paints such as watercolor and tempera, they can also be used with oil paints. The best soft-hair brush is the sable, an excellent choice for fine detail and smooth surfaces because it points and shapes so precisely that you can maintain control over the brush marks. Sable brushes are soft, strong, and flexible; and if properly cared for, they will last for years. A satisfying and less expensive alternative is a sable-blend brush. Other soft-hair brushes are ox, squirrel, pony, and camel. In general these brushes are inferior to a sable, but are worth examining to assess their suitability for your needs.
Synthetic-hair brushes are also available. These brushes attempt to imitate the qualities of sable and bristle, and although they are not yet equal to natural bristle or sable, manufacturers are continually refining their products and new developments frequently reach the market. And considering the expense and increasing rarity of high-quality natural hair, synthetic brushes are worth some experimentation. They are especially desirable for use with acrylics because synthetics can withstand the frequent use of solvent and required cleanings.
When buying brushes, keep in mind that a brush is probably an artist’s most important tool, and it is worthwhile to invest in the highest-quality brushes and take good care of them. More expensive brushes are probably more economical in the long run anyway, because inferior-quality brushes will perform poorly and wear out quickly.