Block brushes include all brushes of square, rectangular or trapezoid shape. Most of these brushes have a long plastic block (ruler); others have a wooden block, usually with nylon bristles, but sometimes from natural hair.
The method of manufacture is insertion. A great deal of flexibility exists with regard to block design. This all depends on customer needs, block dimensions, type, length and density of bristles, and more.
Most block brushes are used in agriculture, the food industry, and flour mills.