A Guide to Watercolour Brushes
Introduction to Watercolour Brushes
Brushes for watercolour painting have shorter handles than oil and acrylic brushes. They are available in a vast range of shapes and sizes for every kind of painting style. Small brushes are useful when painting details and other intricate marks. Large brushes will hold more liquid. They work well for broad brushstrokes and washes for skies.
Traditionally, sable hair was used because it holds lots of liquid. Today there are plenty of synthetic alternatives, as well as brushes that have a blend of natural and synthetic hair.
For a watercolour beginner, a brush set with a variety of shapes and sizes is a great start. This will get you started and as you paint more you will begin to discover which brushes are your favourites. You can then build on your collection of brushes with the right shapes and sizes for your way of working. The price of brush sets varies wildly. They start at cheap prices and can go up to hundreds of pounds. The best quality natural hair brushes, such as sable or squirrel, are the most expensive. Synthetic brushes offer a great hardwearing alternative.
Watercolour Wash Brushes
The most popular watercolour methods require huge amounts of dilute colour. The brush is loaded with paint and water, and then applied to the paper in thin washes. For watery techniques, artists should use a brush with good liquid holding capacity.
Natural hair brushes are superior to synthetic hair brushes for liquid holding capacity. Natural hairs have a central structure known as the Medulla. This is covered by a thick layer known as the cortex. This is in turn encased within the cuticle, which is made up of lots of tiny scale-like fibres. The hollows and indentations found on the surface of the cuticle pick up water and pigment well, which is why natural hair is considered the best for liquid holding. Soft fine hair is favoured for washes as it has less of a ‘snap’. This will create gentle fluid marks with no crisp edges.
Squirrel Wash Brushes
Squirrel hair is often used for wash brushes. Each individual hair tapers to a fine point and is wider in the middle. This contributes to the liquid holding capacity. The fattest part of a round brush is often referred to as the ‘belly’ of the brush. The tapering of the squirrel hair to a fine point means that the brush itself will also taper to a fine point. This makes squirrel mop brushes perfect not only for broad washes of colour, but also for finer detail work, such as lines and dots.
Cheaper Squirrel hair brushes with blunt tips that don't taper to a fine point may be made from previously cut squirrel hair. These are not suitable for detailed work. Squirrel mop brushes are bound in a quill ferrule with twisted brass threads to replicate the traditional brush manufacturing processes of the past. As well as round mop brushes, squirrel hair is also used to make oval shaped wash and bright/flat brushes. This allows the artist to make broad rectangular marks on their work.
Most squirrel hair for brushes comes from Canada or Russia. The Kazan Squirrel hair is the finest variety of Squirrel or Petit Gris hair. It is brown-black in colour. Squirrel hair brushes are incredibly soft; they are so soft that they are often also used in make-up brushes. The downside of this characteristic is that there is next to no ‘snap’ or ‘spring’ in the brush hairs, they don’t ‘ping’ back into place in the way that a synthetic brush might. This means they are not as good for dramatic or punchy marks. It is not the kind of hair you would use if you were looking for a brush that enabled you to have full control over your painting. Something like a spotter, where the brush hairs are very short, and therefore have greater spring anyway (irrespective of what hairs are used) allows you to have full control of where your paint goes onto your work, and is ideal for detail work.
Sable Brushes
One big advantage of working with sable hair is its ability to hold a lot of liquid. This is useful for broad washes of colour. The reason why sable hair holds a lot of liquid is down to the soft, fine hairs. You can easily see this when you immerse a sable brush into a glass of water. It may take a few seconds of moving the brush in the water, but soon enough the hairs of a round brush will fan out. You will see that the hairs are so soft and fine that they are lifted by the water. This also means that water can easily be held between each hair as the brush is lifted from the water – hence the impressive water-holding ability.
What is a Kolinsky Sable Brush?
A Kolinsky is a different animal from a sable. It is a weasel from the mink family native to Asia. Their tail hairs are used to make the finest watercolour and make-up brushes. Male Kolinsky hair is used for the very best Kolinsky brushes. This is due to its strength, slenderness (which contributes to liquid holding capacity), and resilience (which contributes to brush lifespan). Most Kolinsky brushes on the market will use some female hair in the mix, at a ratio of around 60:40 male to female.
Brushes that state ‘Tajmyr’ or ‘Tobolsky’ before ‘Kolinsky’ in their description are referring to where those particular Kolinsky are from. Kolinskies from the River Tobol (Kazakhstan) and Tajmyr in Siberia are known to possess hairs with great elasticity and fine tips. This makes them well suited to delicate and detailed watercolour painting. They hold sharp points and achieve crisp edges. They also have an excellent colour holding capacity.
Other Natural Hair Brushes for Watercolour
Goat hair is an inexpensive natural hair that is suitable for wash brushes. The low cost of the brushes is thanks to the wide availability of the hair. Goat hair brushes are most likely to vary in terms of the quality available. Many manufacturers will make and sell goat hair brushes made from the second cut, i.e., the hair will not taper to a fine point. The result is that the brush head will spray and have a rounded end. Many of the cheapest watercolour brush sets for schools will contain a goat hair brush that looks like this.
On the other hand, a goat hair brush made from the first cut and from good quality hair will taper beautifully. These are considered a close substitute to the finest squirrel hair brushes. Goat hair is soft yet resilient. The majority of goat hair used is white, but some brushmakers also offer dark goat hair brushes.
The painter Ron Ranson, famous for his use of the goat hair hake brush in his work, once found that many Chinese hake brushes were fluffy when new, and required a lot of wearing in before the hairs of the brush possessed the sleekness he sought in his hake brushes. His own hake brush as made by Pro Arte claims to not need any wearing in. It is great for painting in bold, impressionistic techniques.
Badger hair used to make watercolour brushes is mostly sourced from China. A high quality badger hair brush is one that tapers to a very fine point. These can be as good in quality as a squirrel or Kolinsky sable brush. The finer the point that each hair tapers to, the more elastic the spring, and the softer the hair.
A good badger hair brush will have hairs that go from pale to dark in colour along each hair. A lesser quality badger hair brush will appear a more uniform grey along the length of the hair. They will also not taper to as fine a point.
The Development of Synthetic Brush Hairs
The use of animal hair in artist brushes has developed over many centuries. Over time, the industry has learnt what hairs are best for each specific application of colour. The use of synthetic filaments started in the 1970s and is now the most common brush hair used by artists.
The History of Synthetic Brush Filaments
The first synthetic filaments for brushmaking were developed by the company Dupont in the USA during the 1950s. These were mainly for the decorating industry. Their development was given urgent impetus when the USA banned the import of Chinese bristle. The primary filament used was nylon (brand name, Tynex). It was extruded, mechanically tapered, and then tipped and flagged to resemble hog bristle.
Today, nylon is still widely used for paint brushes. But for artist and cosmetic brushes, this filament is not a good alternative to natural hair. This is because it is too stiff and has no fine tips.
The breakthrough for the artist brush market started in the 1970s; Dupont found a way of chemically tapering polyester filaments. But, as the market was seen as being too small, Dupont sold the patent to Toray Industries of Japan. Toray developed the process with input from Japanese brush companies, notably Takamoto (who used their brand name, Taklon). The only other company to produce chemically tapered filaments at that time was Teijin. Because their filament was slightly different, it didn’t infringe on Toray’s patent rights. During the 1980s, Toray licensed the patent to a Korean company, Kolon. Once the patent expired in the 1990s, many other firms began to use this process.
Over the past few decades, the industry has become heavily involved with the use of synthetics. Many artists feel synthetics are more hygienic than animal hair, and more ethical. Artist brushes need to be able to apply a spectrum of media, from very wet to quite dry mediums. This has led to some challenges in replicating the features of animal hair. We can now incorporate many features into synthetic fibres, such as different diameters, taper ratios, crimps, hollows, etc. This means it’s now far easier to replicate the natural features of animal hair. However, animal hairs have some attributes that are hard to imitate completely.
The Challenges of Replicating Natural Hair
The real holy grail is trying to replicate Kolinsky sable. This hair has unique characteristics which make it the best hair to use in fine artist brushes.
An artist is looking for various facets in a brush:
- A fine point
- Retention of the point
- Paint/water holding and release
- Strength/snap
- Durability and control
Kolinsky is the only hair that manages to do all this well, due to the unique structure of the hair. It has very fine cuticles along the follicle which control the pick-up and release of paint. It also possesses a belly, meaning the hair is thin at both the root and tip end. So, when the hair is put into a brush ferrule, the belly sits in the middle. This gives the required strength/snap. It is now possible to create synthetics with scales on the fibres, but many believe that nothing compares to pure Kolinsky.
In many brush ranges, you will see synthetic replacements for most types of hair. This includes sable, badger, squirrel, hog, etc. All these replacements are made using similar polyester filaments, but are adjusted to resemble the animal hair. So, for example, a mongoose imitation hair has a thicker diameter to resemble the hair’s strength. It is also dyed five to six times to match the colour. Heavier gauges of synthetic brushes can replicate the hollow core that natural mongoose hair has. This acts as a well for the paint. However, it is harder to reproduce this hollow in lighter gauges.
Another hair that is not easy to imitate is hog bristle. The best type of hog bristle comes from South West China and is known as Chungking. It is very stiff with fine flags that make it perfect for oil painting. In order to replicate the bristle, a heavy gauge fibre is required. It then needs to be either ground or mechanically tipped to split the ends open.
Squirrel hair is the softest of all hairs used. The challenge for filament producers is to extrude an extremely fine filament that still has enough strength to make a brush. A very light wave is added to the extrusion, and anti-static agents are added to stop the fine filament from splaying. This creates a good alternative to squirrel hair.
Natural hairs are becoming more and more expensive, and so more artists are moving towards synthetics. As this happens, the investment in the technology that is developing synthetic fibres is increasing. This means the quality of synthetics is only going to get better in the coming years.
Synthetic Brushes for Precision, Spring, Detail, and Expressive Marks
Synthetic hair will not have the scale-like cuticle layer that natural hair possesses. That being said, some of the recent developments in synthetic hair manufacture have attempted to replicate this. The outcome of this is that synthetic hair brushes simply do not hold as much liquid as natural hair brushes. However, these brushes do have their place in watercolour painting. They possess a greater spring and are more resilient. If looked after, they can have a much greater lifespan.
The features of synthetic fibres make them suitable for techniques that demand greater control and crisper, bolder marks. Toray hair is a very fine nylon hair which is great for detail and crisp marks. Pro Arte’s Prolene hair is another popular type of synthetic hair. It is a brown glossy nylon hair, which is soft and fine. It has impressive spring and resilience. Similarly, the Jackson’s Studio Synthetic Brushes possess these qualities. After trying them out for the first time, a lot of artists see the benefits of using both natural and synthetic hair brushes in their practice.
Mixed Hair Brushes
Mixed hair synthetic-natural brushes are more affordable than 100% natural hair brushes. They can also offer a greater snap to the brush and are more likely to last longer. There are some mix brushes that use different natural hairs, either to keep costs low or to take advantage of the qualities that each hair possesses.
Watercolour Brush Shapes
Round
Round brushes are formed of a cylinder of hairs that taper to a point at the end. Round brushes are the most popular and most common shaped watercolour brush. The smaller sizes are particularly well suited to fine detail, while the larger sizes are great for washes. All are good for lines of varying thicknesses. The size of the marks made with a round brush can be controlled by the amount of pressure applied when pressing the brush to the surface being worked on. Retractable travel watercolour brushes tend to be round in their shape.
Flat
Another versatile brush shape is the flat. A larger flat brush is ideal for washes. When painting with watercolour, this brush is often thicker so it can pick up a larger amount of pigment. It can be wetted before picking up the paint, so that thinner layers of pigment can be applied to a surface quickly. Wash brushes typically have a squared side edge. This means they are also capable of creating controlled strokes with a solid edge when used with opaque pigments.
Smaller flat brushes utilise a longer bristle length to lay flat patches of colour smoothly, achieving a squared edge. They’re also great for producing long, smooth strokes. This allows for a sense of gesture and motion when applying the paint.
Liner
Liner or rigger brushes resemble round brushes, except they are much finer. They usually have longer hair. This allows the brush to carry more pigment, which enables the artist to paint long and flowing lines. This is a great way to add detail and dynamism to your work.
Mop
Mop brushes have soft bristles with a rounded head. When used with watercolour, they’re an effective brush shape for covering large areas of the surface with thin paint, referred to as a wash.
Angled
Angled brushes are one of the most versatile shapes. They are sometimes an overlooked brush when bought as part of a set. Their inclusion is both helpful and necessary.
The angled shape allows for quick transitions between thin and thick lines. This makes them a great choice for those interested in painting the natural world and other organic material. Whether you want to create motion in blades of grass by flicking your brush at an angle, or block in an area of sky, angled brushes can be very useful.
Additionally, their shape can be helpful in transitioning from a desk to an easel. An angled brush allows for a greater sense of control when working at an upright surface. This affords you comfort when using the fine end of the brush for detail work or text.
Dagger & Dagger Striper
Dagger brushes are shaped like a filbert with half of the bristles missing at an angle. They’re useful for creating teardrop shapes, moving from a wide rounded edge up to a fine point.
They’re often used in botanical painting, helping to create shapes in flowers and leaves with a natural sense of flow. You can load a dagger brush up with multiple colours at a time and drag it across a surface to create expressive shapes. This is useful if trying to capture a sense of motion in something like a still life. Dagger brushes are also a great shape for creating abstract work using multiple colours. Their unique shape means that you can load pigment in different areas of the brush and pull single marks that introduce new colours throughout the line.
A dagger striper is almost the same shape except with a more defined angle of cut on the bristles. These brushes, as the name would suggest, are excellent for painting lines or stripes.
Stippler
Stippler brushes have short, rounded heads. They come in a range of densities dependent on the hair used to make the brush. Often used in painting foliage or fur, stippler brushes are a shape most associated with creating texture. Used in a dabbing motion, this shape is able to create dense, wiry textures, dependent on the colours used, as well as the speed.
Hake Flat Brushes
Hake brushes are used for ‘fast and loose’ styles often associated with Chinese painting. Brushmarks are made sparingly whilst still serving the purpose of describing the subject as fully as possible. Often made with very soft white goat hair. Useful for washes and backgrounds.
Travel Brushes for Watercolour
Watercolour painting is especially well suited for painting en plein air. This is because the kit can be small and portable and the work dries before you need to pack it up to take it home.
A collapsible travel brush usually converts from a short pocket size to a longer brush. It is ready-to-use by reversing the cover that is over the hairs to attach as the handle. Not only does this save space, but it protects the fine hairs of the brush. A few brushes are ‘retractable’, in that the end pulls back inside the handle, rather than moving the cover to become the handle. ‘Retractable’ is an accepted term for all types of travel brushes that go from short to full size.
Most brush manufacturers make a type of travel brush. Pocket brushes by some of the best brushmakers include Da Vinci, Escoda, Jackson’s, Isabey, and Pro Arte. If your brush has a good point and a full belly, you can often use one size brush for a range of marks and washes. So a size 6, 8, or 10 can do double duty as both a wash and fine line brush. There are even handy water brushes that store a small amount of water in the hollow handle, so you’ve no need for a bottle of water.
How Do I Clean My Watercolour Brushes?
Watercolour brushes are most often made from synthetic, sable, or squirrel hair. Their softness means they need more care when handling. Natural sable and squirrel brushes require special care.
Watercolour brushes can be cleaned by removing excess paint with a cloth before rinsing in a jar of water. Blot the brush and rinse until there is no more colour coming out of the brush.
You shouldn’t need to use brush soap after every painting session. In fact, sable and squirrel brushes contain natural oils which can be stripped by frequent cleaning. Avoid using regular household dish soap if you can. When you do use brush soap, be sure to rinse it out thoroughly, as soap products can destroy the sizing of watercolour paper.
Tips for Taking Care of Watercolour Brushes
- Avoid leaving the brush soaking in water. It can crack the handle and loosen the ferrule, and the brush hairs could get bent.
- Some pigments might stain your brush even after thorough cleaning. This doesn’t affect how the brush can be used.
- Reshape the brush while it is wet. It is normal for natural sable watercolour brushes to splay out slightly when dry, but they will come to a point when wet.
Read 'Brush Cleaning Tips for All Mediums' to learn more.
Glossary
B
Blending
The technique of softly mixing one colour into another. Often done with a damp brush to create smooth transitions. Easier when the paint is still wet; blending mediums or gum arabic can extend open time.
Body Colour
An opaque watercolour or gouache. Used to add highlights or correct mistakes. Often refers to white gouache mixed with watercolour.
C
Colour Strength
Also called saturation. This refers to the ratio of pigment to binder in paint. Strong colours appear vibrant and clean, while weaker ones may look dull or muted.
D
Dry Brush Technique
Applying paint with a brush that is relatively dry. Creates a chalky, textured effect. Ideal for rough textures or highlights over washes.
F
Flat Wash
A smooth, uniform application of diluted colour. Often used as a background wash or for laying base tones.
G
Glazed Wash
A transparent layer of colour applied over a fully dry area of a painting. Used to alter the hue or unify sections.
M
Masking Fluid
A removable liquid used to block out areas of paper from paint. Once dry, paint can be applied over it; when the painting is dry, the fluid is peeled away to reveal the untouched paper.
Mass Tone
The appearance of a paint colour in its thickest or most concentrated form. This is typically seen straight from the tube.
S
Staining Colour
A strong pigment that penetrates the paper fibres, making it difficult to lift or alter once dry. Useful for layered washes.
Synthetic Hair / Fibre
Man-made brush fibres. Offer spring and resilience. Often created to mimic the properties of natural hair, such as sable or squirrel.
U
Undertone
The subtle hue revealed when a paint is spread thinly. This colour may differ from the mass tone and can affect mixing and glazing.
W
Wet-on-Dry
Painting onto dry paper. For sharper, more controlled edges and details.
Wet-on-Wet
Colour is applied to a wet surface, allowing pigment to spread and blend unpredictably.