Brushes used for acrylics, like those favored by oil painters, have long handles that allow the artist to work at a distance from the canvas. Acrylic paints are more caustic than oils, so acrylic brushes are designed with synthetics and bristle. Fitch and sable are generally used only with oil paints.
As a rule-of-thumb, acrylic brushes are usable in other mediums, particularly oils, while brushes designed specifically for oil painting and watercolors are unsuitable for acrylics.
Acrylic paints are less costly than oils, and dry more quickly. Acrylic paints can also be used with mediums other than canvas and paper. This has sometimes encouraged artists to work on a giant scale. For large scale works, the larger sized brushes are far less costly with synthetic fibers and bristle.