Angular Sash and trim brush. Ox-hair is the softest, most supple natural animal hair used in Purdy brushes. Specially formulated and carefully blended with our softest white china bristle for just the right amount of resiliency. Perfect for Ultra fine enamel and Varnish projects where an extremely smooth, exquisite finish is desired. From fine artistry to enameling or staining furniture, doors or woodwork, nothing can match the glass-like finish produced by these luxuriously soft bristles. Ox-hair is the softest, most supple natural animal hair used in Purdy brushes. Angular Sash and trim brush.