This set of 3 hog bristle spalter brushes is suitable for oil colour and acrylic colour. Spalter brushes are very wide, flat brushes that can be used to paint large areas or to prime your workspace with. The set contains the following types and sizes: 3 spalter brushes in sizes 30, 40 and 50. Hog bristle (also called bristle) is a sturdy type of hair used for thicker paints, such as oil and acrylic colours. The hair is strong and resilient and leaves a visible brush stroke in the paint.