One of the Four Scholarly Treasures of Chinese painting is the brush. For any painter the brush is a basic tool. The humble brush, a tuft of hair on the end of a stick.
Brushes are the source of endless debate, natural or synthetic, what size, what shape, who makes the best?
For my own use I am comfortable with the better quality synthetics. They may not match true Kolinsky sable, but the are clearly better than the cheap brushes. From what I have read today's sable may not be as good as yesterday's sable in any case. The quality of a sable brush depends on the quality of the weasel's winter coat. Sable farms are in warmer climates than the range of the wild sables that were formerly trapped. The result is animals that do not produce quite as thick a coat.
Chinese brushes are another story. The hair they are made of sounds exotic, and in some cases is. Bear, weasel, wolf, rat wisker, baby's first hair cut, sheep, goat, wild horse mane, white cloud, rooster feather, peacock, orchid-bamboo... The best brushes are made individually by hand. In China decent brushes can be had very cheaply compared to prices in the States. The inexpensive brushes I picked up for the equivalent of $5.00 or less were easily the equal of $20-$40 brushes here in the US.
I have found that after trying quality brushes the cheap ones of poor quality are almost impossible to use. A good brush become an extension of the artist. A poor brush must be fought every step of the way.
It is an unfortunate truth that the only true test of quality for a brush is to use it. Most brushes are shipped with size or starch in the hairs to protect them during shipping. This must be soaked out of the brush before the brush can be tried. Some art suppliers are happy to let customers soak and try brushes before buying, others frown on the practice.
Buying brushes of known and reputable makes is the best bet. But, poor brushes can still slip through. The sad thing is that there is no way of knowing it is a poor brush until it is used. Even epert brush makers occasionally get an unepected failure.
A further aspect of brushes is size and shape. I paint very small works, but I am a fan of big brushes. A big brush will hold more paint. This lets you produce longer, firmer strokes. A quality brush, even if large will still come to a needle point. This point is very capable of producing fine lines with a light touch.
My go to brush for painting ATCs is my half-inch flat. That's right, a half inch brush for a painting only 2 1/2 3 1/2 inches! 5 strokes side by side will span the whole width. But using the edge and corners as well as the flat I can get a huge variety of marks. It is far from being the only brush I use, but it is the most versitile for the size I paint.
In Chinese Ink Painting I use a wider variety of brushes on a single painting. I will load different brushes with different tones of ink, different mixtures of tones, and use a variety of sizes to produce varied width strokes. The width of teh stroke is limited by the width of teh brush, so when I want wide, full strokes I reach for a full bodied brush. Fine strokes require only that the brush come to a fine point.