For many of my book illustrations I have used pen and ink with watercolor as my media. With watercolor, I usually apply the paint first as washes, and then in a dry brush technique. My brush arsenal for this method? Two brushes: a big fat one, and a smaller one. The big fat brush I use when I have very large areas I’m covering in an even wash. It’s a Winsor & Newton Sceptre Gold brush made up of both sable and synthetic bristles. But almost all of my work is done with the smaller brush. That workhorse is a Winsor & Newton Series 7 sable watercolor brush, in a size 4. The Series 7 brushes are very pricey. But one brush will last me through an entire book’s worth of strenuous art-making, still holding its point and behaving as beautifully at the end as it did at the beginning. The other argument in favor of this brush is its remarkable facility, flexibility, and responsiveness. To me, it almost does the painting for me. I try to explain to students that instead of buying those bushels of mediocre brushes that they so often seem to own, they should spend the same amount of money on just one good brush. It’s all you need---and it's the difference between a plywood box of a violin, and a Strad.
When I employ acrylic as my media, my repertoire of brushes is just a bit larger: 3 synthetic-bristle Winsor & Newton brights, and a tiny sable brush, size 00, for fine details. All Winsor & Newton brushes are among the most expensive brushes one can buy. But again, as I say to students: sit on an orange crate if you must; use an old plank for your desk; store your supplies in a grocery bag. Save your money for the three things that really make a difference: good brushes, good paints, and good paper.