A watercolor wash can look easy enough: dip the brush, put it on the paper, drag the color. But how much water is on the brush can change everything. A lot of water can overwhelm the shape, move pigment toward the edges, and cause backruns when the surface starts to dry. Not enough water causes the brush to drag on the paper, creating dry, patchy strokes rather than a solid area of color. Learning to recognize how much water is on your brush is one of the most helpful things you can learn early on in watercolor, because this can affect any kind of wash: flat, graded, glazing, or even a small controlled shape.
Before you begin, examine the brush and the mixture on the palette. Even a round brush that is completely full of water can hold a surprising amount of water if it has a large belly. After rinsing the brush, gently touch the bristles to the side of the water jar, or a paper towel, if it is dripping. Load the brush with your mixture. Ideally, you want the brush to have enough water to glide across the paper without leaving behind puddles with each stroke. You want the brush to feel full, but you don’t want to see water coming out of the tip of the brush before you even get to the paper.
The paper can tell you a lot as well. Paint a small rectangle of color on a piece of scrap watercolor paper and observe the surface right after you have applied the stroke. A good wash will have a slightly shiny look while it is wet. If you see a large drop of water accumulating at the bottom of the rectangle, your brush or mixture probably has more water than you need. If the surface quickly loses the shine and the brush starts skipping, you likely have too little water. Textured cold-pressed paper can exaggerate this effect, because the brush has to cross over a bumpy surface. Hot-pressed paper has a smoother surface, which can sometimes disguise the issue, but you will still notice if the surface is unevenly diluted.
Here is a helpful exercise: paint a number of rectangles using the same mixture, but vary the water-to-pigment ratio. Use the palest mixture for the first rectangle, add a little more pigment to the second, and so on until the last rectangle has a much higher concentration of pigment. Keep the brush load the same for each rectangle, as much as possible. This helps you distinguish two separate issues: how wet your brush is, and how strong your mixture is. A pale wash doesn’t necessarily need a dripping brush, and a dark wash doesn’t need to be bone dry. They’re related, but they aren’t the same.
Another helpful indicator is the edge of the flat wash. A nice, small bead of liquid along the working edge can help you blend your strokes. But if the bead gets too big, and the color starts to run, remove a little water from the brush. If the edge is already starting to dry before you reach it with the next stroke, increase the brush load, or use a bigger brush that allows you to cover the shape in fewer strokes. Going back and forth over a drying wash can cause unevenness, and it can even damage the surface of the paper.
Your paper’s moisture also plays a part. Painting wet-on-dry allows you to control the edges of your shape, but you need to have enough water in your brush to paint smoothly. Painting on damp paper means your brush load can go further, and the edges will soften. Painting on visibly wet paper means any additional water can easily cause unpredictable movement. So the amount of water on your brush can mean different things depending on the situation. Test your mixture on scrap paper before you make an important stroke; notice if the brush releases water slowly, or if it starts pooling immediately.
You’ll know you’re getting better at controlling the water if you start to anticipate how the brush is going to behave before it touches the paper. Notice when the brush has too much water, when you need more pigment, when the paper is too wet for another layer, and when a drying wash shouldn’t be disturbed. For your next session, pay less attention to the end result of the painting, and more attention to the relationship between the brush load, the water on the paper, and the size of the shape. Those observations will make future decisions about watercolor much easier to manage.
