Watercolor brush choices can take up whole aisles in your local hobby store, but don't let that overwhelm you. This page will help you learn about brush types, brush materials, brush sizes and which to choose for your goals, brands, which brushes are the best, and what will work for you.
First, let's talk about watercolor brush types. The most common are the flat brush and the round brushes, and then there's the more specialized fan, filbert, rigger and scrubber brushes. There are, of course, other kinds of brushes, but these are the ones I've used or seen other artists use.
Watercolor brush numbers correlate to inch/millimeter sizes, but it depends on the manufacturer. For instance, a round Loew-Cornell #10 might correlate to an inch size of 7/32" or 5.6mm, but in another brand, a #10 brush might be bigger.
I think the best thing for a beginner is to go to the hobby store and spend some time looking at the brushes offered. Think about what kind of paintings you'll be doing and try to choose brushes that you think will help you achieve your artistic goals.
One of the things to consider is how much water and paint a brush will hold. Oil paint and acrylic paint brushes won't work for watercolor because they won't hold a water/paint mixture well.
Along with my favorite professional artists, I think round watercolor brushes with a pointed end in the sizes of 0-8 are the most useful brushes to have. The brush I use the most is a Loew-Cornell #6 round with a nice point. But then I do a lot of detail work in animal portraits. If you plan to do flower paintings, filbert brushes might be the best for you.
If you work on big paintings, a larger round brush like a Joe Miller signature #32 brush or Princeton Neptune Quill #8 might be best. See this video from artist Lorraine Watry for more info on using larger brushes and brush brands.
Watercolor brushes are made from either natural fibers such as animal hair or from synthetic fibers. Brushes containing blends of these two materials are also available, and are becoming more popular.
I think one of the most important factors is whether a brush will hold onto its fibers when you start using it. Having to stop a beautiful, smooth wash and pick out a brush hair is annoying to say the least! This is one of the reasons I think it's important to buy good brushes specifically for watercolor painting. The cheap ones are just more aggravating than I can stand.
Here's a picture of what happened when I used a cheap Royal & Langnickel Taklon synthetic brush. I bought them because of the sharp point and because they cost a dollar. (I know, you get what you pay for...)
My hope was that because of the brand name, they wouldn't shed. I was wrong. Grrr. But that point does give great control..
Watercolor brush quality can be measured somewhat by the price of the brush. Kolinsky natural red sable brushes are the most expensive brushes. Other natural sable brushes are not as expensive, but still cost more than synthetic and other types.
Sables are expensive because of how they are made and the source of the hair, the Siberian weasel. Back in 2012 or so, the US Fish and Wildlife service banned the importing of kolinsky sable brush hair over concerns about species endangerment.
Although the ban had more to do with politics and documentation and not a true species emergency, it has now been lifted. However, knowing that animals have to die to make those natural sable brushes makes me want to choose synthetic fiber ones instead.
Other types of natural fibers used in watercolor brushes include hog's hair, squirrel hair and ox hair. I don't have any in my brush collection, and don't know much about these but I'm sure Google does.
Synthetic fiber brushes (taklon) are smooth and soft but don't hold up as well to rough treatment. In the past, synthetics were less popular, but in 2020, newer technology has really made them contenders in the best-brush race. White taklon brushes are firmer than golden taklon brushes. The golden taklon brushes are designed to act more like sable.
Finally, brushes which utilize a blend of natural hair and synthetic fibers are becoming more popular, and they generally work well for most watercolor techniques.
If you are careful with your brushes, they can last a long time. Here are some tips on brush care:
Brush brand loyalty is really a subjective, individual choice, driven by individual experience. So I'll just note here which ones I use. The brands that I have in my container include:
My favorite are the Loew-Cornells. If you need more information on brush choices, search out videos or blogs by your favorite artists and find out what they use and recommend. I found that to be very informative when I was just starting out.
Now you can go yonder, and shop for watercolor brushes with confidence.