Bill Martin's Guide to Oil Painting
Good Brushes Make Good Paintings
Brushes are the most important part of your equipment. A good painter will have difficulty painting with bad brushes. A good brush for oils will retain its shape when loaded with paint and will bounce back to its original shape after each stroke. A bad brush will not return to its original shape when loaded with paint or after each stroke. Or worse will not bend at all.
Different Brush Hair for Different Purposes
There are two types of hair used in oil painting brushes. They are BRISTLE hairs from pigs and SABLE hair from the weasel like sable. In the course of a painting you start with large areas. Bristle brushes are best in sizes of a half inch wide or larger so are used to begin a painting. Whole paintings can be painted using only bristle brushes but if you want finer detail in smaller areas, you switch to sable brushes. Sable brushes are best in sizes one half inch in width or smaller. Sable brushes are your detail brushes. (Sable brushes made for watercolors usually lack the spring needed for painting with oils.)
Long Handles Balance the Brushes
Oil painting brushes are made with longer handles than watercolor brushes or house painting brushes. These other brushes are ideally used in a vertical position with the painting surface horizontal. Liquid goes down hill, so the short handles shift the balance toward the front of the brush so the paint will flow better. Oil painting brushes are used in a horizontal position with the painting surface vertical. The oil paint doesn’t flow. When you hold your oil painting brush horizontally the long handle serves to balance the brush in your hand.
Imitation Hair Brushes Can Be Good
Many brush manufacturers make brushes that imitate the qualities of Bristles and Sables at a lower cost. They include nylon hairs, horsehair and mongoose hair. None are as good as sables and bristles but occasionally they come close.
Brushes Come in Different Shapes
Brushes and Their Strokes
A FLAT brush has hairs arranged in a rectangular shape that is longer than it is wide. From the side it is narrow. The Flat is the most versatile of brushes. You can make a broad stroke, a narrow stroke and, with a little twist, a triangular stroke. This is also your primary blending brush.
A FILBERT looks like a Flat with the corners rounded. The stroke is oval shaped or half circular. They are used when you want a softer edge or for smaller blends than you get with a Flat.
A BRIGHT (named after a fellow named Bright) is like a Flat except the hairs are shorter and the side view is narrower. A Bright is used when you want your brush strokes to show. They tend to put the paint on thickly and when worked too hard will remove as paint much as they apply. The bright, being short and therefore stiffer than a Flat, can also give you a little more control of your stroke.
Although some people successfully use ROUNDS for their entire painting, they are less versatile than other brush shapes because little variation in the size and shape of the stroke is possible. Rounds are most often sable hair and are used for small details and line work.
These soft sable-like brushes are used for varnish and retouch varnish. Clean the varnish from the brushes with turpentine then wash them in soap and water.