A wide, flat-tipped wall brush is best suited to wide, flat surfaces. Choose this brush for painting interior or exterior walls and ceilings, broad-board fences, and other wide surfaces. Wall brushes are usually 4 inches wide, usually a minimum of 7/8 inch thick and less tapered than what has been known as in the paint industry as varnish or enamel brush.
Bristle Paint Brushes are constructed with natural bristle, the best of which comes from China. It should only be used for applying oil-based paints or oil based clear finishes such as varnishes. Avoid using natural bristle with latex-based or water thinned paint products because it will absorb up to 40% of its own weight in water, causing it to be too soft to paint well. Rough surfaces break the tips off natural bristle so it will not produce a smooth glass like finish.
Black Bristle is slightly stiffer than white bristle. The tips have thicker flags than white bristle. It is excellent for high productivity in oil based interior and exterior applications.
White Bristle is softer and more flexible that black bristle. It has thinner feather like flags on the tips. It is excellent for fine finishing on the interior with oil enamels, urethane and varnishes. It is also used for fine finishing on exterior high gloss smooth surfaces.
Gray Bristle is a cost effective blending of unsorted bristles that are fine for maintenance grade utility work with oil and rust resistant primers and enamels. It is softer than black bristle, and stiffer than white bristle.
How To Choose The Right Paint Brush For The Job