This section is from the book "Cyclopedia Of Architecture, Carpentry, And Building", by James C. et al. Also available from Amazon: Cyclopedia Of Architecture, Carpentry And Building.
It is worth noting that this committee, made up equally of expert paint manufacturers and experts employed by the large consumers, unanimously agreed that no larger brush than this should be used in making paint tests.
The use of brushes five inches wide is common for outside work; but while such brushes may be had of the best quality, they are heavy and laborious to use, and the workman who uses such a brush will not brush the paint sufficiently to get the best result. If a flat brush is used, it should not exceed 3 1/2 inches in width; and three inches is better. A good 2 1/2-inch oval varnish brush is a most excellent brush for all large work in either paint or varnish. The painter should also have a good 1 1/2-inch oval brush for smaller work, and a number of round or oval brushes, called sash tools, of different smaller sizes, for more delicate work, such as sash and frame painting. Stiff-bristle brushes, which have been worn off short, are suitable for such work as rubbing-in filling. For varnishing large surfaces, flat bristle brushes 2 1/2 inches wide are good; also similar ones 2 inches, 1 1/2 inches, and 1 inch wide are useful. All flat brushes should have chiseled edges.
For flowing varnish, it is necessary to have thick, flat, camel's-hair brushes, running up to 3 1/2 inches in width, although most house varnishing may be done with brushes not over 2 1/2 inches wide.
Besides paint brushes, the workman will need some ordinary scrubbing brushes and one or two painter's dusting brushes, to have the surface properly cleaned.
Steel-wire brushes with stiff steel wire instead of bristles shaped like scrubbing brushes, are used for cleaning off old paint and for cleaning structural metal work. These are of various sizes; and the steel wires are of different lengths and sizes, hence differing in stiffness.
They may be had at hardware stores.