This set of 5 hog bristle brushes is suitable for oil colour, acrylic colour and gouache. The set contains the following types and sizes: round brush in size 6, 2 cat tongue brushes in sizes 10 and 14, 2 flat brushes in sizes 10 and 14. 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.