using acrylics

colour mixing

colour wheel | using different whites | tint strength | add some sheen | desaturate with earthtones | consider transparency | use a glazing technique

Achieving brilliant colours with artist’s acrylics:

start with a warm and a cool of each primary

naphthol light red	quinacridone red	hansa medium yellow	hansa light yellow	ultramarine blue	phthalo blue

A quick lowdown on some technical terms:

• pigments - very small insoluble particles; the raw material that gives paint its colour.
• hue - colour, independent of how dark or light it is, or how dull or clean it is.
• saturation - the degree of a colours brilliance or dullness independent of its hue.
• tonal value - how light or dark a colour is.
• medium - the clear body of the paint without pigment added. Used to extend paint - to make a colour "go further", or as a final coat.

colour wheel

A colour wheel shows the spectrum as a circle of gradated steps. This model can help us to examine the relationships between different colours and is often used by painters as a colour mixing exercise. The twelve colours in this wheel were made from blends of the six pigments shown in the squares above. When mixing colours it is sometimes important to employ a minimum number of hues to create a much larger range. In the modern printing process for example, the three inks used are the cool primaries: a bluish red, a greenish blue and a greenish yellow. It is possible, when painting, to achieve a full range of colour using the three pigments that are closest to the "process" primaries. But by adding three more colours; the warm primaries, a larger and brighter range with fuller colour saturation can be created with greater ease and considerably less work. While an overall understanding of process printing colours can be valuable, it is not necessary for painters to use such a restricted palette when such a large array of pigments are available. If three colours can create a wide enough range in printing, why not use just three when using paint? In printing the white of the paper is used to lighten colours, while painters usually add white to create light colours. When coloured paint is mixed with white paint, the white pigment particles block some of the colour. This makes the advantage of the extra colour saturation in blends created with six primaries rather than three, especially evident. A colour palette with a warm and a cool hue of each primary is an excellent starting point for blending a wide colour range.

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using different whites

Zinc white is a more transparent pigment than titanium white. Because light can pass through zinc white particles, they allow the coloured pigment particles in the mix to be more visible. Using titanium white to lighten colours produces a more "pastel" effect because more of the colour is blocked by titanium’s opaque particles, producing a mix that has better hiding qualities, but a less saturated colour. For more examples see comparing zinc and titanium white.

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tint strength

phthalo blue	10% phthalo blue 90% titanium white
ultramarine blue	10% ultramarine blue 90% titanium white

Pigments differ from each other in many ways, one of which is tint strength. These examples show a high and a low tint strength pigment of a similar colour. Each mix was made with the same proportions of colour to white. High tint strength pigments, though usually more expensive are more powerful, stronger, colours and so "go further" when extended with mediums, diluted, or used in tints. Low tint strength pigments are often more natural looking colours and because they are usually more opaque, have better coverage. Low tint strengths are easier to work with when making precise colour adjustments in small increments.

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add some sheen

naphthol red medium & raw umber blend	the same blend coated with gloss acrylic medium

When a painted surface is matte, light is scattered when it reflects off its surface. All colours can be made shinier by adding gloss medium to the paint or by adding a coat of gloss medium to the surface. Notice how the example with gloss has more colour and the feeling of depth. By making your painting shiny you will allow more colour from within the paint to reach your eyes and less light will scatter from the surface. See applying acrylic medium in the technical tips section.

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desaturate with earthtones

hansa medium yellow	hansa medium yellow & yellow oxide	hansa medium yellow & mars black

When you don’t want bright colours, what do you do? There is more than one way to adjust colours to make them less saturated (duller). The trouble with using black is that it often shifts the colour as it dulls it down. By choosing an earth tone pigment that is a similar hue to the colour that you wish to dull, you can desaturate without shifting the colour. Yellow oxide is good to desaturate yellows, for example, while red oxide, is good to desaturate reds. Raw titanium is a white that has not been fully bleached. It can be used as a convenient way to lighten colours and desaturate them at the same time.

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consider transparency

quinacridone red	naphthol light red

Pigments have many different properties, one of which is their degree of transparency, or translucency;how much light will pass through the pigment particles. Here is an example of a more transparent pigment, quinacridone red, next to a more opaque pigment naphthol light red. The transparent pigment seems to glow, with an undertone of a fuller and lighter colour - you can see into the paint layer. The opaque pigment reflects light off the top surface and not from within - the white of the paper is hidden. Opaque pigments are often less bright, more natural looking colours, which are better able to hide the underlying surface.

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use a glazing technique

Phthalo blue applied in three different ways:

By diluting paint with clear acrylic medium or water and applying thin translucent layers onto a white or light coloured background, you will achieve a lighter colour, while keeping the colour saturation high. The phthalo blue square above, which was lightened by glazing, appears to be more brilliant than the one lightened with titanium white to the same tonal value, which has a more "pastel" appearance. This effect is most pronounced when using high tint strength transparent pigments.

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