I’ve had lots of questions about brushes lately, so I thought I’d quickly cover some basics today and then we’ll do another video tutorial next week. For simplicity’s sake, I’m going to refer to brushes for oil painters here, but most of this information applies to almost any other kind of painting.
There’s a lot to know about brushes. And yet, once you know it then it becomes pretty simple. It’s a bit like Harry Potter choosing a wand– the most important factor is how it feels when you’re using it. And armed with the right information, you’ll be able to make magic with these brushes, too.
Most brushes are built with a handle, a ferrule (the metal part that holds the bristles) and the brush head (which is another name for the filaments or the little hairs). When buying brushes you want to pay attention to the handle and the ferrule first. Is the ferrule wobbly where it attaches to the handle? Pick another brush. Is the paint chipping from the handle? Pick another brush– this likely means the wooden handle has been exposed to water and will swell. Handles are longer for oils and acrylics (for painting at an easel) and shorter for watercolor (since you’re painting at a desk).You want a seamless ferrule, made of metal that won’t rust. This keeps paint and liquids from damaging the structure of the brush.
Now as for filaments, it’s a little more complicated but it still basically comes down to three choices.
Material, Shape, and Size.
Material is first. The filaments can be made of soft animal hair, hog bristles or synthetic materials like nylon. There are advantages to each kind and it’s a good idea to have a few of each in your toolkit.
First, let’s talk about natural. There are two kinds of natural bristles–hog bristle and soft animal hairs like sable. Sable brushes have a nice spring and keep their shape very well. They’re expensive, but when cared for they’ll last years. They are best for details and precision. Hog bristle is usually white in color, and stiffer. They’re good for pushing paint around quickly and leave a distinct mark in the stroke. They’re pretty bristle-y (if that’s a word) and very durable. They work well for large surfaces or for thicker paint.
Most brushes in art supply stores are synthetics. Synthetic brushes are made from nylon or polyester and they’re much cheaper than softer animal hair brushes. For example, I’ve had a combination of synthetic and hog bristle brushes in my studio for years, but just bought my first sable this year. I only own one sable, and I’ve been really happy with my synthetic brushes for years.
A side note: In the store, often brushes are stiff and starched, which helps protect them in transit. Before buying a brush, run it through your fingers and make sure it will hold its shape without that starchy stuff on it. Feel it– if you don’t like the way it feels, pick another brush.
Shape is the second factor in choosing a brush that makes you happy. It’s good to have a variety available, but you’ll find with experience that you prefer certain shapes and sizes.
Here’s a quick diagram showing the different shapes in my brush jar today.

Finally, size. There’s no standardized system for brush sizes. Different manufacturers may each make a size 8 round and yet one will be obviously larger than the other. It’s annoying, but just know that the larger number means a larger brush. Looking through my brushes, I have lots of sizes 4, 8, and 10. You’ll find the size of the brush as a number on the handle, usually it’s close to the ferrule. And in a perfect example of inconsistent sizing, here are these two brushes.

Both round, one is hog bristle and one is my sable brush. They look to be about the same size, yes? And yet, one says it’s a size 4 and the other is labeled as a size 16. Bah. Again, just find the brush that works best for you. Don’t get hung up on size.
Next week, we’ll talk about brush strokes and technique and I’ll offer recommendations on a few brushes for getting started.