Dosage (Water Control) 101

The most important key to getting the results you want in watercolor is understanding how water interacts with your paint. More or less water can completely transform your results. So it’s important to understand how much water you’re adding, and where you’re adding it. In this post, I’ll tell you as much as I’ve learned so far about this skill – although ultimately it’s one of those things where you just have to get your brush wet and get a feel for it!

A note on terminology: Most people call this skill “water control.” Personally, I’ve been trying to get away from the language of power and control when I talk about watercolor. I don’t like to feel adversarial with the materials, as if I’m struggling with them or subduing them. I prefer to think of water as my collaborator. After all, I am asking it to do some of the work and add its own creativity! So I’ve decided that when I refer to the amount of water you add to your painting, I will use the word I heard used for it in French language Youtube videos, dosage. (French accent optional.)

There are three places you can put more or less water to change your results: in the paint, on the paper, or on the brush.

Water in the Paint

Water in the paint is straightforward: more water = thinner, more diluted, lighter-colored paint, and less water = thicker, more vibrant, darker-colored paint.

I created different values of Indanthrone Blue by slowly adding water into a pile of paint on a mixing palette. At its thickest, with minimal water added (just a mist to rewet), the paint is almost black. As water is slowly added, the swatches become lighter colored until they reach pale, sky blue.

Many guides refer to paint consistency with a metaphor involving dairy products. “Yogurt consistency” is paint right out of the tube. Add a little more water and you get cream consistency, then whole milk, 2% milk, and skim milk. I don’t know if I’m intimately familiar enough with various types of milk for this to be helpful, but there you are.

Water on the Paper

In the wet-on-dry technique, the paper is left dry, but in the wet-on-wet technique, you add a layer of clean water to the paper before touching paint down. This adds another factor to consider: the amount of water on the paper.

I created the same gradient from DS Phthalo Blue Green Shade to DS New Gamboge with three different amounts of water: lots, medium, and dry (no water).

If leave the paper dry (like I did in the rightmost box on the chart), you will get clear, hard-edged brush strokes. Perfect for making precise shapes, but it’s impossible to get those soft edges and smooth gradients that is so characteristic of watercolor.

If you slap on a ton of water before you paint, like just lots of water (like I did in the leftmost box on the chart), you are in danger of making puddles. In the “Lots” example, my water formed a large puddle which moved blue paint down into the yellow are of the gradient, then just sort of sat there and took forever to dry. Water continued to move to the edges of the puddle, leaving white splotches in the middle of the puddle, and drying as a hard-edged bloom outlined in a dark army-green color (an inadvertent mix of the two shades). While this is an interesting effect, it’s not exactly what you want in a gradient.

The middle box shows a reasonable gradient made from a moderate amount of water: Blue on the top, yellow in the middle; both colors fade toward the middle, where the mix as green. (There is a quick color jump under the green which I probably could have softened if I’d worked a bit more quickly – the yellow had partially dried by the time I pulled the blue down.) The amount of water I went for here was just enough to make the paper evenly shiny – but not enough to see any visible puddles.

By the way, if you get overzealous splashing water down before a wet-on-wet wash and you do get puddles, there are 3 ways to deal with it before you begin painting:

  1. Absorb. Twist the corner of the paper towel into a sort of wick and just touch the end of it into the puddle. It will get sucked up into the paper towel like that.
  2. Redistribute. If there are wet spots and dry spots, wipe off your brush (so you don’t add yet more water) and then use the brush to move the water around, flattening out the puddles into the dry areas.
  3. Wait. Water evaporates, so if you don’t like how much water there is on your page, just wait a minute. Unfortunately, you can’t make only the right water evaporate. The perfectly-shined areas will dry first before the puddles begin to disappear, but once the overall amount of water goes down, you can redistribute the remaining puddles. If the page dries completely, no worries – it’s a chance to start over with new water.

Water on the Brush

Did you know? Your brush also holds water! Of course it does – that’s what makes it a good watercolor brush. If the brush didn’t hold water, you’d have to be constantly dipping it. For me personally, this is the most overlooked source of excess water in my painting. I can get my wet-on-wet sheen exactly right, but then I’ll introduce new puddles with an inadvertently sopping brush.

Top line: With a sopping-wet newly-rinsed paintbrush, I painted out lines of DS New Gamboge, DS Phthalo Blue Green Shade, and then the blue again wet-on-wet. Second line: the same colors, but with a brush that was wiped dry before dipping into paint. Third line: The same colors again, with a bone-dry brush.

When you paint out colors with a wet brush – say, one that you just rinsed to get another color off – you are apt to add lots of clean water to the pigment well and/or right onto your painting. The effect of wet, juicy paint might be just want you want to achieve, but if you’re painting details, or you have carefully calibrated the wetness of your paper for a gradient effect, extra brush water can douse your plans. To avoid surprise puddles, get in the habit of always blotting/wiping your brush on a dry cloth or paper towel after you rinse it in water.

In Powerful Watercolor Landscapes by Catherine Gill and Beth Means (which I have mixed feelings about, see: language of power), they go even further and advise that you avoid rinsing your brush with water as much as possible:

“Avoid the water jar! A lot of strength in a watercolor painting is diminished by dipping your brush into the water jar without thinking. The only time you need to pick up water is to make a new mixture on the palette, to intentionally lighten a mixture already down, or to clean your brush. Clean your brush as little as you can get away with. Wipe the brush on a paper towel rather than dip it into the water. When you do clean the brush in water, maker sure it is ‘thirsty’ before you do anything else.”

A “thirsty” brush is a damp brush – not wet, just damp – so called because it “picks up paint like a damp sponge.” This is the kind of brush that’s most efficient to dip into your paint to charge up your brush. A dry brush won’t pick up as much paint and a wet brush will discharge water.

(You can also use a thirsty brush to pick up paint out of your painting if you make a mistake! If you need to pick up more than one brush’s worth of paint, remember to wipe it again before you make a second brush stroke. It’s not thirsty anymore once you’ve picked up paint. At that point you might think of it as a “charged” brush – ready to put down whatever it just picked up.)

For a drybrush effect, like in the bottom row of the chart, you’ll want to start with a bone-dry brush. To change colors, use only the cloth or paper towel to wipe – once your brush is damp, it won’t do that kind of texture anymore. You’ll have to get out a brand new brush or wait for it to dry. (Or I guess you could dry it with a hair dryer. It’s hair.)

Now that you understand the three places to vary water in your painting and the effect of each one, you’re well positioned to be a better collaborator with your good buddy, Water!

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