Red long handled synthetic kolinsky filbert brush. Filbert brushes are similar to a flat brush; however, the bristles are slightly rounded at the tip, With its soft rounded edges, the filbert is suitable for blending and figurative work. Kolinsky "finest" hair brushes are made from the male hair only, but most brushes have a mix of about 60/40 male-to-female hair. Kolinsky bristles tend to be pale red in colour with darker tips. The hair is obtained from the tail of the kolinsky. Sable (finest) usually used in watercolour, it can also use for oil and acrylic.