The Size 8 Gainsborough Oil & Acrylic Flat brush is made from Chungking hogâ€s hair. This Professional-grade brush is generally the best choice for oil and acrylic paint due to the flags that hold color. The strong, durable brush easily manipulates heavy paint. It has a unique taper that causes the bristles to interlock, which maintains its original shape and helps control the placement of color. Flats are similar to bright brushes, but the hairs are twice as long as the width. You can hold more paint with each brush stroke, and have more flexibility when creating long lines. Since 1905, Grumbacher has been a brand trusted by students, professors, art conservationists, and professional artists throughout the United States.