Whether you paint in watercolour, oil or acrylic, it is very easy to look at a colour and think that all you need to do is mix X and Y. For the right result, a really good understanding of basic chromatics – the business of colour and tone, what happens when we mix colours – is essential, especially when painting flowers.

Helebores by Candlelight, watercolour on Saunders Waterford Not 300gsm, (22.5x33cm).

In the text I refer to establishing the contrast between dark and light tones. Here they are adjacent – the leaf and the candlelight. The dark is full of colour, including red in the green, and is laid direct onto the white paper, thereby preserving its freshness.

Colour

For instance, choose the wrong red and the wrong blue to mix a violet and you produce a brown. How come? It takes a specific red, ie a blue red like permanent rose, to mix with a specific blue, ie a red blue like ultramarine to make violet – in any medium. A ‘wrong’ red such as cadmium red has yellow in it; if you mix this with a phthalo or Prussian blue, which also has yellow in it, you will mix a tertiary colour, which will invariably be brown. Three primaries equal tertiary, and too much red means brown, so be very conscious of which mixtures you put together. Suffice to say, if working with primaries and secondaries, don’t overmix or you will regret it.

Colour tests

This sheet of colour tests demonstrates the fresh colours necessary for flower painting.

1. Lemon yellow, cadmium yellow, cadmium red, permanent rose, ultramarine, phthalo blue

2.The result of mixing a yellow red (cadmium) with a yellow blue (phthalo) to make a violet. No go!

3. A blue red (permanent rose) plus a red blue (ultramarine) produces a violet. Voila!

4. Tertiary greens are all too common in flower painting – a result of a red yellow (cadmium) and a red blue (ultramarine) is okay but can make greens look dull

5. A tertiary orange (blue red + blue yellow) is good for flesh but not oranges

6. Go for a yellow red (cadmium) and a red yellow (cadmium) for a true orange. Don’t fiddle with it as these are semi-opaque

7. A true green – yellow blue (phthalo) plus a blue yellow (lemon) – will help relieve the dead tertiaries

8. Subtle red additions to a true green to add variety. Choose reds that relate to the specific flower. Add subtle red by introducing cadmium yellow (a red yellow)

9. Darkening reds and yellows: for yellow use either a pale true green (lemon and phthalo) or yellow orange (cadmium red plus cadmium yellow). For the red start pale, cadmium red and progressively deepen the tone (less water), then introduce permanent rose, culminating in a violet (bright violet by Shin Han)

10. Some simple flowers using alternate hues, eg cadmium red plus a tiny touch of permanent rose for a poppy, put in whilst wet

11. Over washing (layering) thinly with alternate hues

12. Basic complementaries. To keep them clean and fresh separate the colours with a white space – if they touch, mud will result

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Tone

Try to keep to a tonal range that suits the subject. I like to establish at the outset what tonal range I am working to. If the range is to be large, ie very black to white, then I establish the dark tone at the outset, direct onto the white paper. If the tonal range is to be more subtle I put down my modified darkest tone, no matter how pale, and stick to it. I find this avoids the habit of starting pale then trying to work up to darker tones by layering, which invariably results in dull dark colours where the layering has produced a tertiary opacity that is drained of all colour. Very dark colours should be mixed and applied fresh to white paper, thereby preserving their transparency, vibrancy and freshness. All the in-between tones benefit from association with the quality of the darkest colour.

By the Creek, watercolour on Saunders Waterford Not, 300gsm, (33x51cm).

Although not a flower painting, a landscape can also benefit from a fresh clean approach. Here I used an abundance of red to really push the greens. Note the large quantity of white, which both encapsulates the primary and secondary colours and also adds sparkle and light to a very shadowy subject.

Pigment behaviour

The issue of pigment behaviour applies specifically to watercolour. The pigments divide into three basic groups: the stains, clean and transparent; the denser semi-opaque; and the precipitating/granulating. The last two groups of pigments can make your painting look mucky in no time if you over layer, mess about when they are wet by trying to change the colour, or use too thickly. My suggestion is to use them only as one layer on white or overlay on stains, and not too thickly. Layering is a lot like mixing and has similar pitfalls.

Firstly, when layering make sure the undercoat is dry – not nearly but absolutely! Mucky paintings are often a result of impatience. The thing to realise is that whatever colour you place on top it has one of two functions: either to deepen the tone of the colour beneath or to change the colour, although whatever tone you put on top will darken the tone beneath. It may be you need a very pale tone to do the job. Don’t necessarily add a darker one or the change will be too abrupt. This is especially so for portraits, flowers or nudes, where ever-subtle changes are required. If you want to change the colour by layering note the same rules apply as for colour mixing. Use colours that are adjacent in the spectrum or go for true secondaries, for instance phthalo blue over lemon yellow, ultramarine over permanent rose, cadmium red over cadmium yellow.

Tools

Good-quality watercolour paper is absorbent, which means that whatever is on your hands is easily transferred. Keep your hands off! Only let the brush touch. Using a graphite pencil on watercolour paper is giving a licence to kill. If you draw in, use a fine sable with a pale colour. Keep a clean sponge to hand for mistakes, together with clean tissue to blot dry.

The palette I use has deep wells for oodles of colour and I put my paint round the edges. I can keep these colours clean and regularly cleaning the palette helps enormously in maintaining fresh colour. Having two water pots also helps: one for brush cleaning, the other for mixing. Don’t get lazy – constantly change your water. And keep your brushes clean as any contamination ruins the colour and causes muckiness.

Note the paper is taped at the corner and only to the inside edge. This allows the paper to expand and contract, stops bleeding onto and off the board and gives a clean, neat edge.

Keep brushes clean. Wash in liquid handsoap and lukewarm water.

Have tissue to hand to blot and keep clean brush ferrules.

This simple, cheap but very useful type of palette has deep wells for plenty of colour. Use the edges for the pigments. Wrap in clingfilm to put in bag.

Two jars of water, not essential but helpful. One for mixing, one for cleaning the brush; change the water constantly.

One final note. I tape my paper all round, not only on the corners. This stops any colour coming off the board and contaminating the picture. If you stick to a few of these household tips your colours should improve.

Good luck!

Paul Riley runs short residential courses from his home and studio in South Devon. Details: tel 01803 722352; email [email protected]; www.coombefarmstudios.com

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