Roger uses a rotational technique to keep the excess finish that builds up on the underside of the brush working for him in the desired direction by building up a wave of finish to keep it flowing at the desired rate in the desired direction. Disposable doesn’t mean low quality. Flex Coat disposable brushes are top quality with extra fine bristles that are trimmed to ⅜” in length and come in two styles. The purple brush has ⅛” bristle cluster and the yellow has a ¼” bristle cluster. The bristles are densely packed into the brush head so that when pressure is applied they fan out on the surface to squeegee the finish smoothly with complete control. Check it out.