How to Choose Your Watercolor Brushes

A good watercolor brush can last you for years, but choosing between so many shapes, sizes and types of hair is not always easy when you are just starting out. Here is a clear guide to understanding what your painting style really needs before investing in your next set of brushes.

Why does brush choice affect your technique?

The brush determines how much water and pigment you can carry in a single load, how quickly the stroke dries and how much control you have over the edges of each brushstroke. Two watercolorists can use the same paper and palette and achieve very different results simply because of the type of brush they are holding.

Brush shapes and what each one is used for

Before looking at the brand or handle material, it is worth understanding what each shape is designed for, as not all brushes serve the same purpose within a painting.

Round brushes

They are the most versatile and are usually the first brushes any watercolorist buys, as they allow you to go from a thick stroke to a very fine one simply by varying the pressure. A medium-sized round brush works for both washes and details, making it a safe choice if you are only going to have one or two brushes.

Flat brushes and wash brushes

Flat brushes have a straight, wide tip and are ideal for covering large areas of color evenly, such as skies or backgrounds. They can also be used to create clean, geometric edges, something a round brush cannot achieve as easily.

Detail brushes: liner and rigger

Liner and rigger brushes have very long, fine bristles designed for continuous lines, such as branches, leaf veins, rigging or signatures. They are not intended to hold large amounts of water, but rather for precise strokes that require a steady hand and light pressure.

Natural, synthetic or mixed hair: what is the difference?

The type of hair directly affects the brush’s water-carrying capacity, the softness of the stroke and, of course, the final price. No option is objectively better than the others; each one is better suited to a particular technique or budget.

Natural hair: Kolinsky, Petit Gris and sable

Kolinsky is considered one of the highest-quality natural hairs because it immediately regains its point after each stroke and holds a large amount of water and pigment without losing its shape. Petit gris, which is more affordable, is widely used for large washes because of its excellent carrying capacity, although it does not offer the same degree of point precision as Kolinsky.

These brushes require a greater investment, but when properly cared for, they can last for decades, which can make up for the initial cost if you paint regularly. In addition, the softness of natural hair reduces unwanted marks that synthetic fibers can sometimes leave on fine-grain paper.

Synthetic fiber

Synthetic fiber brushes are the more affordable alternative and work particularly well for structuring shapes, lifting highlights or working on details, although they traditionally hold less water than natural hair. Modern fibers have improved considerably, and there are now mixed versions that combine natural and synthetic hair to approach the carrying capacity of more expensive brushes without significantly increasing the price.

Brush size and numbering: how to read the numbers on the handle

The number indicates the thickness of the brush’s hair bundle, but it is not a universal standard: a number 8 brush from one brand can be noticeably different from the same size from another. For this reason, it is better to focus on the actual thickness and the shape you need rather than the number printed on the handle.

As a general reference, low numbers (0 to 4) are suitable for detail and fine work, medium numbers (6 to 10) cover most everyday painting, and larger numbers (12 and above) are designed for washes and large formats. If you mainly paint on A4 or smaller paper, you will rarely need a brush larger than a number 12.

The basic brush set according to your skill level

You do not need to buy an entire store’s catalog to start painting with confidence. This is a reasonable starting point depending on how long you have been practicing:

• Beginner: a number 8 or 10 round brush and a one-inch flat brush cover most basic exercises.
• Intermediate: add a small round brush (sizes 2–4) for details and a rigger for fine lines.
• Advanced: add a natural-hair brush such as Kolinsky or Petit Gris for washes and greater pigment control in larger paintings.

Care and maintenance to make your brushes last longer

Brushes, especially natural-hair brushes, are one of the most durable investments in your watercolor supplies, so it is worth spending a few minutes looking after them after each painting session. Proper maintenance prevents them from losing their point or developing splayed bristles prematurely.

Avoid leaving them soaking in a water jar while you paint, as prolonged exposure to water can loosen the glue that holds the hair bundle inside the ferrule. You should also avoid storing them wet in a closed case, as this can encourage mold growth in natural hair.

• Rinse them with lukewarm water and a mild brush soap specifically designed for brushes after you finish painting.
• Shape the bristles with your fingers while they are still damp and let them dry horizontally or with the tip pointing downward.
• Store them in a ventilated brush holder, never in a closed tube while they are still wet.

Common mistakes when buying watercolor brushes

Finally, keep these common mistakes in mind before completing your next purchase, as they are often the reason a brush ends up sitting unused.

• Buying many brushes at once without being clear about what technique each one is designed for.
• Choosing solely based on price and automatically ruling out natural hair, even when your technique would benefit from it.
• Failing to test how well the brush point snaps back into shape before buying it.
• Using a flat brush when precision is needed, or a rigger when you need to cover a large surface.