Usually, the same brushes can be used for oil and acrylic painting. Brushes for watercolor will be labeled as such. There are two basic kinds of oil/acrylic brushes: bristle and “sable” brushes. Bristle brushes are harder and off-white colored; “sable” are brown and much softer. Real sable brushes are made from the hairs of minks. Sabeline or Sablette is often mixed with synthetic hairs. Brushes come in other types of hair, such as ox or camel (actually made from cattle and squirrel, goat or pony, respectively). These types are not as good a quality brush, for control reasons, but they are generally cheaper. Brushes are a very personal thing with painters – try different ones and see which you like best. There are also different types of brushes: rounds, brights, flats and filberts. As well as those designed for custom uses, such as fan brushes. These different shapes have certain attributes better suited for one technique or another. Rounds are good for line work, and detail; brights and flats are better for massing larger areas and sharper edges; and filberts, if you get a good quality one, are good for linear painting and large masses, even in the same stroke. Brights and flats have square edges – good for more structural painting, like Cezanne. Hairs on brights are slightly shorter than flats. For a rounded, softer feel, rounds and filberts do well. Sizes of brushes are numbered on the handle – the smaller the number, the smaller the size (generally from 1 to 10-16 or so). Try a wide variety of them especially in the early stages of painting