A waterbrush is unlike any other brush. It consists of a familiar-looking bunch of bristles at the one end, but the handle isn't solid wood or plastic. Rather it's a container or reservoir designed to hold water. The two bits screw together, and the clip-on cap stops the water leaking out when you're not using the brush.
As you use the waterbrush, water gradually seeps down from the reservoir onto the bristles. This means the brush bristles are permanently moist or damp.
Different brands of waterbrush look more or less the same, and all work on the same principle. The size and shape of the water reservoir will differ between brands, as can the size of the brush bristles.
The bristles of a waterbrush are normally just moist or damp, they're not dripping wet (Photo 1). The water seeps gradually and continuously from the water reservoir down into the bristles, keeping them moist.
To get more water in the water brushes bristles, you squeeze the water reservoir. (As you can see in Photo 2, this particular waterbrush even tells you exactly where to push.) Basically, you move your hand up a little way along the brush handle, then squeeze with your fingers. Though this feels odd at first, you'll soon get used to this action when painting with the brush.
How much additional water is pushed down onto the bristles depends on how hard and long you squeeze the water reservoir. As you can see in photos 3 and 4, the bristles will hold a fair drop of water before it drips off.
Just how moist the bristles are in a waterbrush depends on the brand. With some the water seeps slower than others, so we suggest trying a different brand if the first one you buy doesn't work well for you. Of the waterbrushes we've got, our favorite is Kuretake waterbrush (used for the photos in this article).
To get lots of water onto the bristles of a waterbrush, you simple continue pressing the water reservoir. Provided it still has water in it, of course! It sounds obvious, but I have got so carried away with painting, I failed to realize the water had run out.
The water will drip off the brush onto your paper (Photos 1 and 2). To avoid puddles of water on your paper, move the brush as you squeeze the reservoir (Photo 3).
When you're adding additional water to paint already on paper, be careful not to squeeze too hard or long, or you can end up with too much (Photo 4). If this does happen, use a corner of a clean cloth, or a dry brush, to soak up the excess water. With practice, you'll soon learn to judge how much water you're going to get.
To fill the water reservoir, hold it under a running tap or submerge it in a small container of water (such as a bowl or mug). It's even easy to do from a small bottle of water when you're painting outside, provided you don't mind splashing a bit.
A waterbrush is ideal for use with watercolor paints and eliminates the need for a separate container of water. This makes it really useful for plein air painting or sketching on location.
The photos above show one of the 12 pans (blocks) of paint in the small watercolor set we use when traveling. If we just want a little bit of color, we touch the waterbrush against the paint. The moisture in the bristles will 'activate' the dry pan paint, and we'll have a little color to use.
If we want a lot of a particular color, we'll drop clean water down into the pan from the brush (Photo 2). How much we mix the paint and water with the brush depends on how dark we want the paint color to be (Photo 3). The more we agitate the water against the paint pan, the more paint 'dissolves' into the water.
To use the watercolor paint, simply dip the waterbrush in and out the paint, like with a normal brush. If you're used to using a sable-haired brush for watercolor, you'll find that the synthetic bristles of a waterbrush don't hold as much paint, so you'll find yourself dipping the brush into the paint more often.
You'll find that a waterbrush can be used to create a flat wash in the same way as a normal watercolor brush (Photo 2). Simply dip the brush in and out of the paint as usual. You'll find that the moisture in the waterbrush doesn't make a difference, provided you don't squeeze the water reservoir and provided you pick up fresh paint with the brush regularly.
It's when you're wanting to paint a graded wash (Photo 3) that the uniqueness of a waterbrush makes a huge difference. You start by picking up some paint and laying this down, then simply continue painting without adding fresh paint or clean water, or rinsing the brush. The water in the waterbrush gets added to the paint as you're working, gradually lightening the color to create a graded wash.
Be careful that you don't squeeze the water reservoir and end up with a puddle of water on your paint (Photo 4).
A waterbrush can also be used to lift color directly from watercolor pencils or watersoluble crayons. Simply place the bristles against the pencil, then move it back and forth until you've got enough paint on the brush.
It will take a little trial-and-error to know just how much paint you've lifted, but always remember you can add more water from the brush while you're painting.
A waterbrush is ideal for turning watercolor pencil into watercolor paint. You simply run the waterbrush over the water soluble pencil, and the water in the bristles turns it into paint. The advantage of doing this with a waterbrush rather than an ordinary brush is that you don't have to stop to load the brush with water.
Photo 1 shows watercolor pencil with a waterbrush run across it just once. Photo 2 shows it having been done several times, which is why there's more paint 'activated'.
Cleaning a waterbrush is easy and fast. Best of all, you don't need a separate container of water to do so.
To clean a waterbrush, start by wiping off any excess paint on a tissue or cloth (Photo 1). Then squeeze the water reservoir so some water runs into the bristles (Photo 2). Wipe the bristles again (Photo 3). Repeat a couple of times, and your waterbrush will be clean (Photo 4).