For the Artist, How To

How to: The Magic Watercolour to water ratio

Sorry, there actually is no “magic formula”. I can’t even give you a definitive answer about how to achieve the right mix of paint and water. Everything depends on your paints and brushes, the techniques you’re using. Even the weather plays a role.

And practice. Lots of practice.

So let’s start at the beginning. Water in your paint comes from three different sources: wet paper, a wet brush and/or your palette. So here are a few things you should understand about those sources.

  • Apply water lightly to the paper to create an even, glossy sheen. If you create a bead or pool, you’ve added too much water.
  • If you’ve applied too much water, allow it to dry to that even, glossy sheen before starting to add colour.
  • Use brushes that are natural hair or a mix of real and synthetic. Pure synthetic brushes don’t  hold enough paint and water and you have to keep reloading.
  • Mix your pigments on a porcelain palette or plate because the paint and water will mix best as opposed to plastic surfaces. You can often get white china plates at second hand shops. If you already have a plastic palette, roughing up the surface a little with fine sandpaper to take the sheen off will help some.
  • Keep a piece of scrap watercolour paper by your palette. Always test your colour before applying it to your piece. If the colour is too dark, add more water. If it’s too light, add more pigment.
  • Practice your scales!

How to Practice

Just like learning to play an instrument, you need to practice your scales. Value scales. This is the quickest way I know to help you get a feel for that paint to water ratio.

A value scale shows all the possible values of a colour ranging from the lightest shades to the darkest shades.

Value scale

Creating value scales forces you to focus on maintaining good water control. So get out your sketchbook and practice, practice, practice.


  • Adding more water lightens the colour
  • Adding more pigment darkens the colour

How to create YOUR value scales

  • Draw a rectangular box on your watercolour paper or in your sketchbook.
  • Divide the rectangle into 5 – 7 individual squares.
  • Start with the darkest wash of the colour you are working with. Put some pure pigment (or highly concentrated pan colour on your palette. Only add just enough water to help you brush on the colour.
  • Paint the first square on the scale. This will be your darkest value.
  • Add just a tiny bit of water to the pigment on your palette. Then paint the second box on the scale. It should be slightly lighter than your first square.
  • Repeat until you reach the last box. This will be your lightest value.

This exercise works with both tube or watercolour pans.

Try working the the other way as well, starting with the lightest and adding pigment until you reach your darkest value. You may find you have a personal preference that works best with your style.

Whichever way you choose to mix your values, you should see a consistent change in the values of the pigment.

Practice your scales until you become well acquainted with the paint to water ratio that you’re using to create a scale and you’ll soon know how to achieve the colours you want in your painting.

I hope this helps.

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