Once you have used tone to suggest three-dimensional form and the illusion of depth you will realise how important it is in the structure of a painting. The greater the contrast of tone within an image the more vibrant and dramatic the final visual effect.

A strong directional light source causes strong tonal contrasts. Bright light through a door throws the rest of the room into shadow. A form lit from behind becomes a silhouetted shape of light against dark. This strong contrast of light and dark transferred to your watercolour makes an arresting painting. A sense of drama is intrinsic in the dark and lightness portrayed.

Mixing dark colours

To create lively dark areas in your painting, forget ready-made colours such as black or Payne’s grey. Instead make those dark tones out of two opposite colours, such as blues and browns, or reds and greens. The effects will be rich, dark, slightly variable washes that are full of mystery.

The combinations are endless, and the colours delicious. Mix lots of pigment with enough water to make a creamy mixture. But take care that it is not too thick or you may find that an unwanted sheen appears on the dried surface of the wash.

Remember that very wet watercolour dries lighter than it appears when wet. So, if you think your wash is going to dry too light and it is still wet, plunge more pigment into the wash wet-in-wet.

These darks can be built up in layers, but too many layers will deaden the colour, so try to reach the colour you desire with your first or second wash.

Suggested combinations to make vibrant darks (see image above):

• Top row:  French ultramarine and burnt sienna, French ultramarine and burnt umber, French ultramarine and sepia, French ultramarine and raw umber
• Middle row:  Prussian blue and burnt sienna, Prussian blue and burnt umber, Prussian blue and sepia, Prussian blue and raw umber.
• Bottom row:  Indigo and sepia, crimson alizarin and indigo, crimson alizarin and viridian

The highlights

It is the difference between the light and dark that counts in a painting using tonal contrast, so pay close attention to the lightest areas. The white paper will always represent your lightest highlights. Demarcate those areas you want to remain white in your preliminary sketch and be careful not to paint over them by mistake.

To make the brightest highlights stand out other light areas can be tinted with thin transparent washes to lessen their brightness.

Chelsea Arts Club, watercolour, (18 x 13cm)
An ordinary subject of a jacket draped over the back of a chair is transformed into a vibrant little painting by the dramatic shaft of light cast across the restaurant floor.

Shadows

Shadows, like the dark areas in a painting, also benefit from being coloured rather than grey. At sunset the blue or mauve cast to a shadow is very obvious, but even during the day shadows are tinted with colour. It behoves the artist to seek out and emphasise these colours, even if at first you do not believe you see them. Watercolour has the advantage of being transparent, enabling you to lay tints of colour over other colours and thus create coloured shadows that can, if necessary, be modified by other colours on top or that shine through from underneath. Remember that overlaying three primary colours will turn them to greys and browns.

Beachcombing, watercolour, (23 x 15cm)

I love to paint silhouettes against the setting sun.  I used masking fluid to hold back the highlights of the sparkles on the water from the all-over yellow ochre and indigo wash.

Colour contrast

Contrast is not just about tone. By contrasting opposite or complementary colours you can also achieve dynamic effects. For a vibrant, colourful watercolour, contrast red with green, purple with yellow or orange with blue.

These contrasts need not be blatant; remember that subtlety and suggestion are very persuasive. An orange flower set in green foliage that veers to blue will be more striking, and look more orange, than if the foliage green veers to yellow. Use the temperature of colours to create contrast, too.  Warm reds placed against cool blues will look hotter than cool reds against warm blues. A painting of a blue sky against a warm yellow ochre beach will look brighter than if you paint the beach with a cold lemon yellow.

Paradise Found, watercolour, (56 x 76cm)

Africa is hot – the hippos are returning to water.  I have used the dramatic contrast of yellow and purple to evoke the excitement I felt at this scene.

Vibrant greys

For mid greys, mix the two-colour combinations suggested above and dilute with more water. Sometimes you will obtain a wonderful granulating effect as the two colours separate grain from grain on the surface of the paper. This adds texture to the shadow. French ultramarine and burnt sienna will often do this, as will cerulean or manganese blue and yellow ochre, but it does not always happen!

Greys made from two colours will have more character than ready-made greys. You can easily veer them towards the colour you perceive the grey to be – for example, a blue-grey or a green-grey – by adding more of that particular colour in the mix.

Singing the Blues, watercolour, (76 x 56cm)

The warmth of French ultramarine is used to paint the shadows of the flowers and pillow. Contrasted with the stronger French ultramarine of the cornflowers and the bright yellow chrysanthemums there is no need to modify the blue towards a grey; it already settles back to become a believable shadow.

Contrast of shape and line

Within a painting contrasts of every kind serve to enhance their opposite number. We have looked at contrasts of tone and colour; what about shape and line?

A painting of soft undefined areas can lack interest, but if you introduce a contrasting angular shape the soft forms come alive. A landscape view of horizontal fields may well be attractive enough, but the vertical addition of a tree makes the composition sing.

These points may seem obvious when you see a naturally interesting view, but there will be times when you need to bring them to mind deliberately to make the composition lively. You may wish to paint a particular scene and you want it to be authentic to the physical nature of the place but the composition is boring. Try lowering your eye-line by sitting on the ground, so that foreground features rise up to cross the horizon and create a greater contrast of shape or line against the landscape. Look for ways that could make the painting more interesting. Trust your own judgement.  If the composition interests you it will almost certainly interest someone else, too.

Danube Delta, watercolour, (20 x 25cm)

This vast expanse of water and marsh fascinated me.  By lowering my eye-line I could break up the soft wet-in-wet wash with angular grasses to bring the sketch to life.