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.
To clean watercolor brushes, rinse them thoroughly in water, then wash them with a mild soap in warm water. Rinse under running water and lay them flat to dry. Once dry, store brushes bristle-end up. Always reshape your brushes before storing to prevent damage to the bristles.
Long handled brushes are recommended for easel style painting giving the artist additional length to stand back from the canvas. Short handled brushes are often used for table-top painting where the artwork is closer to the artist, and lies flat, such as with watercolor painting. Either type of handle that is most comfortable to the artist can be used.