Watercolor Brushes 101

Of the major categories of watercolor supplies (paint, paper, brushes), brushes were the last ones that I got into. Actually, I put it off, improving my paints and papers while continuing to use cheapo brushes from the discount bin (which I chose based on the color of their handle.) It just seemed complicated! There are so many brushes with various attributes, and I had no way of telling what’s good and bad about them.

Well, I’ve now done my research, so if you’re still stuck where I was six months ago, let me break it down for you! 

Watercolor brushes differ from each other in three main ways:

• Shape: The shape of the tip. Different shapes make different marks on your page.
• Size: The size/diameter of the tip, which affects how large of a line it can make at one time.
• Material: What the bristles are made of: natural animal hair or synthetic (plastic).

Shape

Brushes come in all sorts of shapes, but there’s just one shape I use 99% of the time: round. The point at the end of the brush means that you can make fine lines and small marks, even with a large brush size. By tilting or pressing down on the brush, you can make larger marks. It’s an incredibly versatile brush. I have them in a variety of sizes.

Still want to explore more shapes? Here’s a quick primer, in order (in my opinion) from most to least useful.

•  Mop (or quill): A softer round brush that holds a ton of water and is useful for putting down large washes, like the sky. Mops tend to be larger than round brushes. Some artists use mop as their main brush, because you can make highly expressive thin-to-thick lines with just one brush; but since it holds more water than a round, water control can be difficult.
• Flat: Rectangular brush that’s good for making straight-edged shapes; useful for urban sketching (buildings, windows, parallel lines as in fences, etc.) A large synthetic flat is indispensible for laying down a flat wash with gouache, though I prefer a soft mop or filbert for watercolor.
• Oval (or cat’s tongue or filbert): A flat, oval brush that may have a domed or pointed tip. A large soft filbert makes a good alternative to a mop for sky washes, because it can cover more ground faster. It’s sort of a middle ground between a mop and a flat.
• Rigger (or script): A narrow, long-bristled brush for making long, fine lines, e.g. ship rigging, power lines. Similar to a round, but the bristles are longer. Also good for star splatter: the long, springy shape seems to distribute stars especially well.
• Liner (or needle, or extended point): Long like a rigger, but with a round belly (reservoir). This allows it to hold more water. Compared to rigger, produces fine lines that are less crisp and more random, e.g. twigs and grass. Good for calligraphy and signing your work.
• Spotter: The opposite of a rigger, this is an extra-short brush, typically found in small sizes for detail work. Offers more control than a longer brush for small details. Good for drybrush since it doesn’t hold a ton of water. May be favored by botanical artists and others who like to work small.
• Angle: Like a flat, but cut at an angle instead of straight across. Sort of a cross between a flat brush and a liner, because you can turn it on its side to paint large areas, or use the edge to paint straight lines. The angle means that long lines are easier than with a flat brush, but flat rectangles are harder.
• Dagger: A long angled brush for swooshy calligraphic shapes. (An especially long one may be called a sword.) Sort of a midway point between an angled flat and a liner. Good for making points, like with evergreen trees. This is Liz Steel’s favorite shape and she uses it as a primary brush. Personally, I find it difficult to use because it’s asymmetrical and I can’t get my mind around it.
• Fan: A fanned-out brush which makes multiple marks at once. Supposed to be good for grass. I find this 100% impossible to use, but you do you. 

After trying all these brushes, I can report that I still use round almost exclusively. I rarely find the other shapes better than round even for the special situation they’re supposed to be good for. I don’t know if this will resonate with you, but I liken it to digital art in Photoshop or similar, where there are a gajillion special effects filters and things you can play with when you first get the program, but when you actually want to do something, it’s the basic tools that you actually use.

Size

It’s helpful to have a few different sizes of round brush on hand. Generally, you need a small brush for detail work, medium size for most painting, and large for putting down a wash of a large area. But how do you translate this into brush size numbers? What does “medium size” mean?? It’s tricky; different people have different preferences about how big they like to work.

“Beginners often try to get by on tiny little brushes – don’t,” Cathy Johnson in First Steps Series: Painting Watercolours. “You’ll want to choose the largest brush you can comfortably work with to paint. It will hold more water and pigment – and cover more ground before needing refilling with fresh paint.”

I was certainly tempted to stick with small brushes at first (they are a lot cheaper, for one thing), but I agree with Johnson that larger brushes are more convenient and versatile. Even the largest pointed round brush still comes to a tiny point, so it can handle detail work, it’s just also capable of working large! I have also found that going up in brush size encourages me to work more loosely and expressively. When I first started, I probably would have said that #6 was the “medium” brush, and now I feel that it is more like #8 or #10.

Note that size numbers can vary from brand to brand. Different brush shapes may have different sizing conventions. My size 4 mop is roughly equivalent to a size 16 round. To compare brands, look for the measurements; companies often provide the diameter or width of the brush head in millimeters.

Here are some of the most useful sizes for each brush shape (in my opinion). Note that I work on 6×8″ paper usually and you may want larger brushes if you work larger. These are arranged roughly smallest to largest.

Brush Shape	Useful Size	Size Explanation
Rigger	2	~2mm diameter
Round (small)	4	~3mm diameter
Round (medium)	8	~5mm diameter
Round (large)	12	~8mm diameter
Mop or quill	4	~10mm diameter
Oval	1/2″	1/2″ or ~12mm width
Flat	3/4″	3/4″ or ~18mm width

Material: Natural vs. Synthetic

Synthetic bristles are made from plastic fibers like nylon and polyester. Natural brush bristles are made from animal hair, usually sable. (A sable is a type of marten, which, if that doesn’t clear it up, is an animal in the weasel family.) The fanciest kind is Kolinsky sable, a special rare type of marten from Siberia. Another common choice is squirrel (also known as Petit Gris). Some brushes uses a mix of synthetic and natural.

Each material paints differently:

• Synthetic varies a lot and can be made in different styles, but it has the capacity to be firmer than natural brushes. It also holds the least water. It can be easier to control, but you have to go back to your water cup and paint box a lot, especially with smaller brushes.
• Sable is springiest and holds the best point, which makes it great for detail work, and holds a whole lot of water, which makes it great for washes as well – it’s a jack of all trades! Generally, this is considered the overall best material for watercolor painting, and most synthetic brushes that are successful are imitating the qualities of sable.
• Squirrel or petit gris is the softest and holds the most water, making it an ideal specialist for large wash brushes. Some artists like to paint everything in squirrel, though I personally find it too floppy for details.

Any of these choices work for watercolor depending on your style and preference. You can find professional watercolorists who insist that natural is better, and those that prefer synthetic. They have a different feel and paint differently, so if your budget allows, you may want to try some of each and see which you prefer. Each material has its place for different tasks and styles.

Here’s a side-by-side comparison.

Consideration	Natural	Synthetic
Brush feel	Softer (especially squirrel); may be springier (especially sable)	Firmer, usually
Cost	More expensive	Cheaper
Quality	Usually fairly high, because it would be a waste to make a low-quality brush out of expensive materials, but can vary.	Varies wildly by brand and model. There are extremely good synthetic brushes, but almost all terrible brushes are synthetic.
Holding Capacity	Due to the structure of the hair, they hold a ton of water and pigment, and tend to release it evenly.	Less porous, they hold less water and need to be rewet more often. They can also create less even washes. Good for drybrush technique.
Ethics	The paintbrush industry sources fur cast-offs from the fur industry that would otherwise go to waste. So while no additional animals are being killed to make paintbrushes, I’d say the ethics are pretty similar to fur or leather. Natural hair is biodegradable at end of life.	No animals are directly harmed, but plastics use oil to produce which causes environmental harm, and plastic brushes will eventually end up in a landfill. I’d say the ethics are similar to other plastic things.
Longevity	High-quality natural brushes can last and hold their point for a long time – like 10+ years – if you take care of them well, but they can be sensitive to improper handling.	Synthetic brushes typically wear out faster (high-quality ones may take 3-5 years instead of 10+ years), but they aren’t as finicky about maintenance.
Other Arts	Oil paint, India ink, liquid watercolor	Gouache, acrylics

You may want to choose a different bristle material for different brush shapes. Here are my preferences for watercolor:

• Softer material (squirrel or synthetic squirrel): large wash brushes, like mop and oval wash
• Springier material (sable or synthetic sable): versatile brushes, like round and dagger
• Firmer material (synthetic): brushes for crisp lines, like flat and rigger

For gouache, I always use firmer synthetic.

Travel Brush Options

Suppose you want to take your brushes with you when you paint outside. You might be interested in these.

Water Brushes

This is a type of plastic travel brush with a hollow handle that you fill with water. To wet the bristles, you squeeze the handle. They’re game-changingly convenient to travel with, because you don’t need a separate water cup. To add water to your wash – or rinse the brush – just squeeze the brush, then use a cloth to wipe off any excess water and pigment from the bristles.

You don’t get much choice over the type of bristles for a water brush (always plastic), and they only come in a few sizes. Some artists hate them, and insist on taking real brushes into the field, along with water containers. I’m in the camp of artists who finds them super-convenient; sure, they don’t paint out as nicely as sable (or even synthetic sable), but for me personally, the choice isn’t between “nice brush or water brush,” it’s “water brush or don’t paint outside because it’s too much effort.”

Travel Brushes

If you don’t like water brushes, you can bring your regular brushes along with you when you travel, or you can buy travel brushes. These are just like regular brushes, but they come with a cover that you can use to protect the bristles when not in use. Typically the cover converts to a handle (some travel toothbrushes work the same way).

Many artist love these (Jane Blundell has a huge collection), but I have trouble getting the covers on in a way that doesn’t separate and damage the bristles more than if I just didn’t use the cover. If I were to travel with non-water brushes, I would just take my normal ones and wrap them in a brush roll.

Brands

There are tons of paintbrush brands! Here are some of the ones on my radar.

Rosemary & Co

My favorite brand! High quality, yet reasonably priced, they offer some of my favorite springy watercolor brushes. The only problem is they’re based in the UK which can make them a bit more difficult to access from the U.S., so I have to wait until I want a lot of brushes and make a big order.

They have several lines. Here are some of my favorites:

• Red Dot – Synthetic sable. My favorite synthetic for watercolor.
• Pure Sable – Relatively inexpensive for how high quality they are.
• Sable Blend – A Goldilocks balance between synthetic and sable. It’s firmer than pure sable, but with more water-holding capacity than a synthetic.

Princeton

Widely available in U.S. chain art stores. Not too expensive and relatively high quality. A good value. All their lines are synthetic.

• Heritage – Versatile, relatively soft for synthetic, and hold water well. They come in useful four-packs or can be purchased individually. Good “middle of the road” brush, not too firm or too soft. Good value. This is the line I’d recommend starting with, and you decide whether to go firmer or softer from there.
• Velvetouch – Firmer than Heritage. Springy, lively. I prefer these to Heritage and I also enjoy using them for gouache. Etchr and Wonder Forest are similar if you can access those brands more easily.
• Neptune – Softer than Heritage. I personally found these to have the downsides of natural brushes (floppiness) without the upsides (springiness), but I know other artists who feel the opposite.

Winsor & Newton

The same famous paint company also makes famous brushes, notably the Series 7, which was supposedly created to be Queen Victoria’s favorite brush. Although I didn’t get into watercolor until 2021, I actually tried size #2 WN Series 7 brush way back in 2010 for inking comics in india ink! I was super-impressed at the time with how much line control you could get from the brush and how great of an experience it was, but I was less impressed when I re-tried it in 2021 as a watercolor brush. It seemed to run out of water fairly fast and had a floppiness that made it less desirable than my Princeton brushes. I am not sure if it’s just better for inking than watercolor, if my standards have risen since I became familiar with more brushes, or if the quality has gone down in the last decade, but as of now I don’t really use this line.

Isabey

A fancy brand, a nice luxury to spring for once you know what you want. I have one brush from Isabey, a petit gris oval wash, and it’s luscious. Soft, holds a ton of water, smooth handfeel. Expensive but high quality.

Escoda

Another fancy brand I’m not particularly familiar with, but they have a good reputation.

da Vinci

Not to be confused with the Da Vinci paint brand from California, the da Vinci brush company is from Nuremberg, Germany. I’ve tried two of their lines, Casaneo (synthetic squirrel) and Cosmotop-Spin (synthetic sable), both times after reading some artist waxing rhapsodic about how great they were and how they’re the only brush they’ll use. In both cases I was underwhelmed. They’re on the nicer end of synthetics but not worth paying three times the cost of Princeton, imo. Maybe they’re cheaper in Europe.

Silver Black Velvet

These synthetic brushes have an incredibly soft handfeel (velvet is apt), making this an unusual brushing experience that some people prefer. Not my favorite personally, but may be worth trying to see if you like it.

My 3 Favorite Watercolor Brushes

[Section added 9/19/22]

At the moment, I have had the same three brushes out on my watercolor table for several months (and dozens of paintings). I have a whole box of other brushes, but I’ve found I’m rarely if ever tempted to stray from my three faves. They are:

• Rosemary Series 401 Sable Blend Round, size 4 – Detail. I could see an argument for using pure sable for a detail brush since it would hold more water, but I find that the increased firmness from the synthetic blend gives me more precision, which I like in a detail brush. This is a great balance of what I like in sable with what I like in synthetic.
• Rosemary Series 99 Sable Round, size 8 – General use. Ideal for laying in the midlayers of a landscape. Soft enough for expressive impressionist strokes but pointed enough for precision. Holds lots of water and paint.
• Isabey 6235 Petit Gris Pointed Oval, size 4 (1/2″) -Perfect sky wash. The oval shape helps it cover lots of area at once, but it still has a point to get into those small areas.

Brush Care Tips

It’s not too hard to take care of watercolor brushes; no special deep cleaning is required. All that’s needed to get the paint off is a simple rinse under the faucet, maybe with a bit of a massage with your fingers. Brush soap is optional – you can treat your brushes to a spa every few months, but it’s not necessary every day.

The main issues are (1) retaining the point, so you can continue to get fine detail from brushes of all sizes, and (2) not letting the handle get waterlogged, which can lead to bristle loss.

Painting

These tips are aimed at preserving your point.

• Mist dry paints with water a few seconds before loading your brush, so you’re loading soft, moistened paint instead of digging into a hard lump.
• Paint at an angle, not straight up and down. Save the point for tiny details.
• Paint with a light touch; don’t press down as you might with a pen or pencil. Think of gently guiding the paint across the surface of the paper. 
• Never leave brushes bristles-down in the water cup! When you’re done painting with a particular brush, swish it in the water cup, blot it on your cloth and lay it down horizontally on the cloth or a brush rest.

Cleaning

These tips mainly concern avoiding waterlogging.

• When you’re done with a painting session, take all your brushes and run them under a gentle stream of water, then gently reshape the tips with your fingers.
• Lay brushes flat to dry with the heads off the edge of the table. Don’t put them upright in a cup to dry, although you can store them upright in a cup once they are fully dry.
• Store dry brushes in an open-air location, e.g. cup, drawer, open bin – anything with air flow.

Resources

Here are some more posts around the web I found useful in learning about brushes:

Shari Blaukopf, “My Five Favourite Brushes”

Liz Steel, “Sketching Tools: Brushes”