Match the Wetness: Controlling Water in Watercolor
Updated: Sep 23
Think of Watercolor Like a Sponge
Watercolor becomes much easier to understand when you think about how water moves through a sponge.
Water naturally travels from a wetter area toward a drier area. If you touch a damp sponge to a puddle, the sponge absorbs some of that water. If the sponge is wetter than the surface it touches, water moves in the opposite direction.
The same thing happens with your brush and watercolor paper.
Understanding this simple principle can help explain blooms, backruns, hard edges, and many of the other surprises watercolor gives us.
Match the Wetness
When you connect one wash to another, pay attention to how wet each area is.
If the paper is damp and your brush contains a similar amount of water, the colors can join softly and naturally.
But if your brush is much wetter than the paper, that extra water will push into the drying wash. This can create a backrun or bloom.
Sometimes that effect is beautiful and intentional. Other times it creates an edge or shape you didn’t want.
The important thing is to understand why it happens so you can choose when to use it.
Why Backwashes Happen
A backrun often occurs when a wetter wash touches an area that has already begun to dry.
The wetter area pushes water and pigment into the drier wash. As the water moves, it carries pigment with it, creating the characteristic branching or cauliflower-shaped edge.
If you want two washes to merge smoothly, try to connect them while their wetness is relatively similar.
Match the wetness.
That simple idea solves a surprising number of watercolor problems.
Learn to Read the Shine
One of the best ways to judge the wetness of your paper is to look at the reflection on its surface.
I like to position my light so I can clearly see the shine on the paper while I’m painting. A glossy surface tells me there is still plenty of water present. As the shine begins to disappear, I know the paper is moving into a damp stage.
Over time, you begin to recognize these stages without having to think about them quite as much.
It takes practice, but learning to read the surface of the paper is one of the most valuable skills you can develop in watercolor.
Want a quick reference for controlling water in watercolor?
I created a free guide to help you match wetness, read the shine on your paper, understand how water moves, and know when to stop working a wash.
Softening an Edge
The same principle applies when you want to soften an edge.
If you bring a brush loaded with too much water into a wash that has already begun to dry, you may create a bloom instead of a soft transition.
Instead, remove some of the water from your brush and try to match the moisture level of the paper. Then gently soften the edge.
The closer the wetness of the brush and paper are to one another, the more predictable the transition will usually be.
Water Wants to Equalize
Water is always trying to find balance. Just as water levels have to be managed before two sections of a canal can connect, the amount of water in two watercolor washes affects what happens when they meet.
Water Control Gets Easier with Practice
Water control can feel mysterious when you first begin painting, but much of it comes down to observation. Watch the shine, notice how wet your brush is, and pay attention to what happens when two areas of different wetness meet.
With practice, you’ll begin to recognize these stages instinctively—and watercolor will start to feel much more predictable without losing the spontaneity that makes it so beautiful.
If you’d like to explore washes, edges, water control, and other watercolor techniques with me in greater depth, I’d love to have you join me at Illuminating Watercolor.
