Pure Kolinsky sable hair, black handled filbert brush. Kolinsky sable-hair brush is a fine artistsXDT paintbrush. The hair is obtained from the tail of the kolinsky use for oil and acrylic. It is generally conceded to be the best material for oil and watercolor brushes due to its strength, spring and ability to retain its shape ("snap"). It has a thick ferrule and hairs that are, on average, medium to long hairs in the shape of an oval.