The Humble Brush

This basic but highly essential decorating tool has been the subject of many myths over the years. If we go back in time to around 30 years ago. Paint brushes in the UK were almost exclusively made from pure bristle. There were of course exceptions with some natural fibers being used for wash down and industrial applications.

If we start with Pure China Bristle. In the UK the most common type was black in color. In Europe white lily bristle was the favored choice. The main source for this natural product was China and still is today. The bristle comes from pigs/hogs that are more akin to wild boars to look at. These animals have naturally growing thick coats.

There are four major regions for bristle in China, each has its own climate giving rise to the thickness, softness and durability of each type of bristle. The most common type is Chungking. The bristle is a bi product as the animals are farmed for food purposes. The animals were allowed to free range and this also gave them strong durable coats.

With the growing population in China, these animals are now more intensively farmed and their life cycle is shorter. This gives bristle that is of a much lower quality and also it becomes much harder to get consistent grades.

The process for bristle once it arrives for manufacture in to brushes is for it to be cleaned and steamed to keep it strait. It usually arrives graded by length and type in round bundles that are called knots. The knots are put in to metal cones and then steamed. This is called boiling and in the very best brushes double or triple boiling is used to give the very best finish to the bristle.

The cone shape is important in this process as the tip of the bristle (the flag) is at the narrower end of the cone and the root at the more open end. This helps the bristle to hold its shape and to aid in giving the paint brush a good sharp head.

It is very usual to blend different types of bristle to achieve different qualities of brush, brushes with 90% tops being at the higher end of the quality scale.  If you look carefully at the tip of a bristle brush you can see that the flag is split, this allows the brush to be softer at the tip to give a good even finish. It also helps the brush to wear in to the shape that the painter is comfortable using. Bristle is an absorbent material, if looked at under a microscope you would see many tiny barbs on the bristle.

This allows the brush to pick up and hold paint until it is drawn over the surface that is being painted because of the absorbent nature of bristle it works much better in oil based paints. It can be used in water based products but because water makes the bristle swell this leads to drag marks when painting.

Today the most common material for paint brushes is synthetic filament. There are numerous types of this material. Several of the better brush manufactures are producing their own filaments to offer a point of difference. Most common in filament types is SRT Solid Round Tapered. This as the name suggests is a synthetic solid fiber that is tapered from its base to its tip. The tip is usually artificially flagged (split) to mimic bristle and also to soften the filament for a finer finish.

Brushes made from this type of filament do not have the holding capacity for paint as with bristle. The straight sides of the filament are easy for the paint to run off of. This is overcome in several ways, the brush heads are more open allowing more paint to be picked up and the gaps between the filaments act as small reservoirs to hold the paint until the brush is drawn across the surface.

Another and more innovative way of achieving an applicator that has good pick up, release and finish is to blend different types of filament. Blends like Technofil do this very well. These are some of the types of filament used:  SRT, mini hollow, x cross etc. By careful blending a synthetic brush can be made to resemble the characteristics of bristle brushes, that is to say they pick up and hold paint and release it evenly giving a smooth fine finish.

This type of brush does not wear down as quickly as bristle but with blended filaments and flagging they do wear down evenly. Synthetic filament will not absorb water and so the problem of swelling does not happen this makes these applicators work really well in water based paints, particularly on finish coats where brush marks need to be kept at a minimum. As paint technology progresses the applicators needed have to also adapt, so it is a continuous process making sure that good brushes are available. As the bristle market continues to decline new innovative bristle replacement filaments are becoming available, definitely something to look out for.

Pioneer Brush is at the forefront of filament technology. We combine years of experience with laboratory testing of filaments from all over the World to find the most effective blends of differing shapes and diameters and can tailor these according to the viscosity of the paint being used in selective tasks. This is why we separate our brushes into “stiff” and “soft” formulations. You will also notice that we categorise brushes into “interior” and “exterior” painting, with thicker and more durable filaments used for the latter.