The early synthetic brushes were poor copies of the natural hog bristle brushes, but with time the manufacturers developed a way to flag (split the ends) the bristles, combine bristles of differing lengths and stiffness which gave the brushes a better taper and feel. Today, synthetic bristle brushes are very good copies of the natural hog hair bristles long used exclusively for the best paint brushes.
Natural bristle brushes
These brushes are still the preferred choice for oil based paint by many professional painters. The natural split ends of the hog's hair bristle holds a lot of paint at the end of the brush, combined with good pick up and release qualities make this a continued favorite for oil based paints. With years of historical use behind them, these brushes are time tested application tools. Natural bristle brushes come in two basic types: black bristle and white bristle. The black bristle is the "general use" bristle used for most solvent paints. White bristle brushes are softer than the black bristle, and are used with thinner viscosity materials such as: shellac, oil varnishes and stains. The softness of the white bristle allows for smoother brushing with light viscosity materials. Generally speaking, the stiffness of a bristle helps in the spreading of the paint, and the softness of the bristles helps with "tipping off" the paint. This fact has led to the development of mixed bristle brushes which combine softer, ox hair bristles with the stiffer black hog bristles in an effort to control the stiffness and softness of the bristle mix.
Synthetic bristle brushes
As a rule, natural bristle brushes are used with solvent paints and varnishes, and synthetic brushes are used with waterbased paints and clear coats. The most common bristles used in synthetic brushes are made of nylon or polyester. Most synthetic brushes are a mix of these two bristle types. Nylon and polyester bristles will usually wear and last longer than natural bristles and they hold up better with waterbased paints. Natural bristle brushes become limp and floppy when used with waterbased paint.. Manufacturers use different types and percentages of nylon and polyester bristles to control the stiffness and the feel of their brushes, and to modify the other characteristics of the brush (pickup and release etc....)
Types of paint brushes
Brushes come in different varieties for specific uses. Bristle amounts, lengths and widths will differ depending on the intended application.
These are used for painting trim and enameling. These are smaller brushes, from 1” to 2 ½” in width, and the thickness of the brush (amount of bristles) is less than that of a wall brush. The sash brush can be either flat (straight end) or angled. The angled brush allows for getting the “point” of the bristles into corners and is considered by many to offer better “cutting in” control.
Wall brushes are wider (2 ½” to 4”), and have more bristles than sash brushes. Wall brushes are intended for larger areas and are used for "cutting in" interior walls when used in conjunction with a roller. Wall brushes are also used for exterior painting of siding and trim. The wall brush comes in the standard flat version as well as in a semi oval version. The semi oval holds quit a bit more paint than the standard flat brush and is good for big brushing projects like exterior horizontal siding and exterior trim painting.
Stain and varnish brushes
These are usually white china bristle brushes and are intended for oil based stains, varnishes and urethanes. These brushes come in widths of 2” - 3 ½” and are softer than black bristle brushes which helps in eliminating brush marks.
Throw away brushes
This is not really a specific brush type, but is a general category of (cheaper) brushes used for touch up or perhaps oil primer application where the brush will not be cleaned out for re-use. The throw away brush saves time in clean up and in used solvent waste, making them an environmentally wise choice.
Some specialty brushes are: short handled brushes that will get into small cramped areas, long handled “hockey stick” brushes for extended reach, chip brushes for stain application, stencil brushes for paint application with stencila. There are many other specialty brushes.
Faux finishing brushes
There are a whole range of specialty brushes made specifically for faux finishing. Among these specialty brushes there are:
Floggers: flat thin brushes used for patting a glaze to create wood pores. These are also used for dragging wood grain or strie / linen wall finishes.
Mottlers: used to put mottled markings in an overglaze for wood graining. Two varieties exist: a wavy “S” curvy type and a straight mottler (which can be converted to an improvised wavy mottler by sticking one’s finger(s) into the bristles).
Softeners: either real or synthetic badger bristle brushes. These are very soft brushes. The tips of these brushes are used for the purpose of softening faux marble and faux woodgraining. There is also a china (hog) bristle softener in which the bristles come to a straight cut, block end. The bristle softener is stiffer, but is used for graining in the same way that a badger brush is used. The bristle softener is also used for dragging wood grain out negatively and for stippling.
Liners: There are many types of liner brushes. Sword liners, round, flat etc…. These are used to add lines to wood grain or marble veining as well as in many other faux techniques.
Stipplers: used to break up glaze and to blend glaze (by stippling colors together). Block stipplers are BIG (and expensive) brushes which are used for wall finishes. There are smaller stipplers (kind of shoe polish buffing brushes) used for smaller substrates.
Overgrainiers: piped or fan overgrainers are used for wood graining either negatively or positively.
Misc. wire draggers, whisking brushes, fan fitches, and the list goes on…….. of the may specialty faux brushes used in the faux finishing arena of professional painting.