The Size 8 Bristlette Studio-grade Oil & Acrylic Filbert brush uses white intermediate-grade, durable Taklon filaments that resist abuse, so it is ideal for use with oils and acrylics. Filberts are a perfect compromise between rounds and flats. They are shaped like a flat with a curved end allowing for more flexibility than a flat. The side can be used like a round and the broad side like a flat. The Filbert brush was invented by the Impressionists in order to have the feeling of a worn in flat with maximum flexibility, and it has become a favorite of painters everywhere. Since 1905, Grumbacher has been a brand trusted by students, professors, art conservationists, and professional artists throughout the United States.