Artist Brushes and Painting Tools | BLICK Art Materials
Three characteristics are used to evaluate the performance of a watercolor brush: how much water/color does the brush hold; does the brush have and maintain a sharp point or edge; and does the brush snap back to its original shape.
Traditionally, the best watercolor brushes are made with Kolinsky Sable. Kolinsky is regarded as the best grade of sable hair. Another option is squirrel, which holds more color than sable but has less snap. Camel hair (which is really pony or goat) is a more economical choice.
Today, better quality synthetic-hair brushes and synthetic-sable combinations can be as good, if not better, than many natural-hair brushes. Synthetics are a more durable, and sometimes a more affordable, alternative to natural hair and still provide a high-quality performance.