Here's a comparison of various popular waterbrushes that artists use.

What are waterbrush good for?

A waterbrush is actually a brush with a water reservoir behind. It's a very convenient tool for artists on the go, especially those use sketchbooks. You have the best of both worlds with the versatility of using a brush without having to bring a separate water supply.

Waterbrushes are best used on smaller pieces of work, and for me that would be smaller than A4. For A4 and larger, I prefer normal brushes because they can control washes more easily. For example, to make a large even wash, with a normal brush, you can use reload with the pre-mixed colours and can be sure that each stroke is of the same intensity. With a waterbrush, even if you pre-mix and reload, water inside the reservoir will continue to flow, affecting the intensity.

One of the main challenges of using the waterbrush controlling the water flow. Getting a flat or gradated wash is certainly possible with a waterbrush but it requires practise.

The other challenge is cleaning the waterbrush when you can to switch colour. This involves wiping the bristles with tissue to get the paint out. Usually I will wipe, then squeeze some water, and wipe again until the bristles are relatively clean. Cleaning a normal brush of course is as easy as cleaning it in a container of water but you have to have bring a container.

The waterbrushes compared

The waterbrushes that I'll compare are in the photo above, from left to right, we have

• Sakura 4ml waterbrush
• Sakura 9ml waterbrush
• Holbein large waterbrush
• Pentel Small
• Pentel Large
• Niji large waterbrush (Kuretake)
• Derwent waterbrush
• Escoda Versatil pocket brush
• Da Vinci Maestro pocket brush
• Mechanical pencil
• 12 half pan watercolour box

I've put two pocket brushes to compare the size. They are actually all pretty small and can fit into a pencil case without any trouble. The Holbein one might feel a bit tight because it's long. None of the waterbrushes can fit into the 12 half pan watercolour box except for the Da Vinci Maestro pocket brush.

By the way, the "large", "medium" and "small" refers to the size of the brush tip and not the size of the brush.

These waterbrushes all use synthetic bristles. There are actually waterbrushes that use a mixture of synthetic and animal hair, but I found them to be of poor quality because the hair keeps falling out, and they leak.

Among the waterbrushes I have, Holben's the only one that use white coloured bristles, the rest are transparent bristles. I prefer white bristles compared to transparent ones because they look and feel more artificial although in terms of performance there's not much difference.

The bristles all taper to a point. For detail work, the transparent bristles are sharper while the Holbein is more difficult to control, relatively speaking.

The largest brush, Holbein in this case, is about size 6 of a normal brush. The normal brush has more of a belly shape to hold water.

Let's go through them one by one listing the pro and cons in point form.

Derwent waterbrush
+ Brush tip comes in three sizes: small, medium and chisel
+ Waterbrushes are numbered so that you can identify the brush tip to pick
+ The squarish cap base prevents the waterbrush from rolling around on the table
+ The body holds a decent amount of water
+ Nice sharp point
- Body a bit tough to squeeze
- No breather holes in the ferrule. Pigment will get pulled back into the ink reservoir

Sakura
+ Brush tip comes in three sizes: small, medium and large
+ Cap is transparent so you can see the brush tip inside
+ 9ml model holds a decent amount of water
+ Nice sharp point
- 4ml model is too short, awkward to hold, like a short pencil
- 4ml model does not hold a lot of water.
- No breather holes in the ferrule. Pigment will get pulled back into the ink reservoir

Niji - Recommended
+ Brush tip comes in four sizes: small, medium, large and flat
+ Cap is transparent so you can see the brush tip inside
+ Body holds a decent amount of water
+ Nice sharp point
- Small cap inside the body makes it inconvenient to refill water from running tap.

Niji is actually made by Kuretake Japan, the company that makes the popular brush pens.

By the way, this is a waterbrush that's commonly rebranded and sold. Meaning, I've bought a few other waterbrushes under other brands and they all turn out to be Kuretake. You can identify Niji/Kuretake brushes easily by the useless clip they stick on the cap.

This is the filter cap you'll see when you unscrew the Niji body. The major downside is that small black-coloured filter cap that acts a filter to the body. There's a tiny hole that provides and control water when you squeeze the body.

If you want to refill from a running tap, you'll have to remove that filter cap, a task for those with longer finger nails. You can still refill without removing that cap but it involves dipping the opening into water and squeezing the body to suck water up, and that's not easy to refill the entire body.

And you cannot use the waterbrush without that filter cap because when you screw the body to the grip, that connection is not airtight, squeezing the body will cause the water to leak from the threads.

I usually bring a few Niji waterbrushes out because of the inconvenience of refilling. Actually, I usually bring spare waterbrushes out for other brands as well so as not to refill water while I'm outdoors.

Notice those clips on the cap? They are stuck to the cap and you can't actually use them as normal pen clips. Peculiar design choice.

Holbein - Recommended
+ Brush tip comes in two sizes: medium and large
+ Cap is transparent so you can see the brush tip inside
+ Body holds a decent amount of water. More than other brands
+ White coloured bristles feel less artificial than transparent ones
- Bristles are thick and not easy to use for detail work
- Gets worn out quite fast
- Not easy to find in western countries

Holbein is my favourite waterbrush because of the white bristles even though it has quite a few disadvantage. My next favourite would be Pentel waterbrushes.

Pentel - Recommended
+ Brush tip comes in three sizes: small, medium and large
+ Different coloured caps differentiates the brush sizes
+ The body holds a decent amount of water
+ Nice sharp point
- Medium-size does not have breather holes

This is a stopper you see in some of the waterbrushes capped to the body. It's useless and you can throw it away.

For some waterbrushes, water might come out from the ferrule that holds the bristles rather than out from the bristles. Shown above is the Sakura waterbrush. Quite a few waterbrushes do that so take note.

Be careful not to squeeze the waterbrush too hard or the water will drop at unexpected places, affecting your artwork.

I normally use waterbrushes with watersoluble media such as coloured pencils, watersoluble graphite. For watercolours, I prefer normal brushes even if I have to be inconvenienced by bring a separate container of water for washing the brush. For sketchbooks, waterbrushes are great.

In the photo above, I've fitted a Da Vinci Maestro pocket brush inside the watercolour box.

Video review

Here's the video review to see the waterbrushes in action.

Conclusion
Waterbrushes offer the convenience of normal brushes with a built-in water supply. They perform more or less the same. Main difference is just design of the body and bristles.

In order of preference, I would go with Holbein first. Then it's a mix between Pentel, Sakura and Derwent. Then Niji because of its refilling system.

If you do detail work, I recommend Pentel or Sakura.

Availability

All links below are direct links to the items on Amazon.

Pentel Aquash waterbrush (US | CA | UK | DE | FR | IT | ES | JP)

Sakura waterbrush (US | CA | UK | DE | FR | IT | ES | JP)

Derwent waterbrush (US | CA | UK | DE | FR | IT | ES | JP)

Niji waterbrush (US | CA | UK | DE | FR | IT | ES | JP)

Holbein waterbrush - Difficult to find, even on eBay.

Search Jackson's Art Supplies (UK) and Utrecht Art Supplies (USA) too.