Designers - an elongated round sable, most common for illustration work. Fan - a flat fan, used for blending, available in both bristle and soft hair. Ferrule - the metal tube which supports the hair and joins it to the handle. Filbert - flat brushes with oval shaped heads, available in both bristle and soft hair. Flag - the natural, split tip of each bristle.
Flags carry more colour and are evident on the highest quality hog brushes.
Goat - an inexpensive alternative to sable for large wash brushes. Interlocked - bristle brushes whose hairs curve inward towards the centre of the brush head. Kolinsky - the highest quality sable hair. Length out - the length of hair exposed, from the ferrule to the tip. Mop - large, round, domed brushes, often made from goat, used primarily to cover whole areas in water colour.