Practical colour-mixing techniques

1Good mixing is a habit

Two students can have exactly the same paints, and one produces clean, glowing colours while the other produces muddy ones that change from one corner of the painting to the other. The difference is not talent: it is a set of practical habits. How you lay out the palette, how much water you use, how clean your brush is and whether you write down your mixes decide the result. Professional muralists and sign writers follow these habits because repainting a wall costs time and money.

2Know your paint

• Poster paint (tempera): water-based and opaque (it covers what is underneath). Cheap and common in schools.
• Watercolour: water-based and transparent (you see through it). Tints are made by adding water so the white paper shows through, not by adding white paint.
• Acrylic: water-based while wet, waterproof when dry. Wash brushes before it dries.
• Home-made paint: every paint is a pigment (coloured powder) held together by a binder (a glue). You can make your own from powder paint or fine coloured earth:
  • Egg tempera: separate an egg yolk, pierce its skin and mix the yolk with an equal amount of water, then mix in the powder on a plate. Painters used egg tempera for centuries. It dries in minutes, so mix small amounts.
  • Glue paint: mix powder with water and a little white PVA glue until it is like cream.

3Set up your workspace

• Palette: an old white plate, a tile or a plastic lid. White lets you judge colours truly.
• Layout: put small blobs round the edge in the same order every time, light to dark: white, yellow, red, blue, black. Keep the centre for mixing and keep the blobs apart so they do not run into each other.
• Two water jars: one to rinse the dirty brush, one kept clean for wetting the brush and thinning paint.
• A rag or newspaper to dry the brush after rinsing, so that drips of water do not thin your next mix.
• A mixing tool: a palette knife, a plastic knife or a flat ice-lolly stick mixes large amounts better than a brush and saves the brush from wear.

4Five mixing techniques

1. Palette mixing: mix completely on the palette before painting. Gives a flat, even colour. Best for large areas.
2. Brush mixing: pick up two colours on the brush and mix them lightly as you paint, leaving streaks. Livelier, less even.
3. Wet-into-wet: paint one colour onto a still-wet area of another so they run together softly on the paper. Good for skies and soft edges.
4. Layering (glazing): let one colour dry, then brush a thin, see-through layer of another over it. A thin yellow glaze over dry blue looks green. Only works with transparent or watered-down paint.
5. Side-by-side (broken colour): place small dabs of two colours next to each other without mixing. From a distance the eye blends them.

5The consistency of paint

How thick or thin paint is, its consistency, matters as much as its colour. Thin paint like milk is for washes and glazes. Paint like cream is right for most painting: it covers well and flows off the brush. Thick paint like toothpaste holds brush marks and gives texture. Add water a few drops at a time: too much water makes poster paint streaky and weak.

6Five habits that prevent mud

1. Rinse the brush and dry it on the rag between colours.
2. Add dark to light, never light to dark, a little at a time.
3. Mix two or three paints at most; more than that usually turns grey-brown.
4. Mix more than you think you need.
5. Test on scrap paper and let the test dry: many paints dry a little lighter or darker than they look wet.

Worked example: matching a colour

Mutesi wants to match the pale blue of a morning sky for a painting of Lake Kivu.

1. Hue: it is a blue, so she starts from blue.
2. Value: it is much lighter than pure blue, so she needs a tint. She puts white down first and adds blue in small touches.
3. Test: she paints a small swatch on scrap paper, holds it up next to the sky and squints. Too dark: she adds more white.
4. Record: the match is 1 part blue to 6 parts white. She needs 21 spoonfuls in all, so each group of 7 spoonfuls holds 1 blue and 6 white: 21 ÷ 7 = 3, giving 3 spoonfuls of blue and 18 of white. She writes the recipe on her colour card.

7Make it: a colour-mixing record card

1. Divide a card into eight boxes.
2. Boxes 1 to 3: mix red with white in the ratios 1 to 1, 1 to 3 and 1 to 7. Paint each and write the ratio underneath.
3. Boxes 4 and 5: paint blue, let it dry, then glaze thin yellow over half of box 4. Paint wet yellow into wet blue in box 5. Compare glazing with wet-into-wet.
4. Boxes 6 and 7: dab red and yellow side by side in tiny dots; view from three metres away.
5. Box 8: match the colour of a leaf, a flower or your school uniform, and record the recipe.

Practice