Wet-on-wet watercolour: how to paint soft washes and flowers

Wet-on-wet means putting paint onto paper that has already been dampened with water. The colour does not stay where the brush left it — it keeps travelling on its own and the edges of every shape stay soft. No amount of blending on dry paper gives the same result.

When the sheet is ready

The whole technique rests on recognising a single moment. You wet the sheet with clean water and wait until the mirror shine is gone and only an even, matt dampness is left. That is when pigment spreads widely and still predictably.

• Standing water — the paint runs everywhere and the shape disappears.
• Matt dampness — the best moment: the wash opens gently and stops by itself.
• Almost dry paper — hard rims appear, the marks painters call cauliflowers.

The mix has to be stronger than usual

On a damp surface every drop is diluted a second time, so what you pick up from the palette should be clearly stronger than the colour you want to keep. Watercolour also loses power as it dries. That is normal, and it is better to allow for it from the start than to correct it later.

Why it suits plant motifs

A meadow seen from a distance, mist over water, the background behind a flower, a soft feather — none of these has a sharp edge. I usually begin with a diffused underlayer and only add the crisp things once it has dried: stems, veins, the outline of a wing. The order of the layers matters more here than the choice of brush.

What the technique will not forgive

1. Touching the wash while it dries — every contact leaves a mark that cannot be removed.
2. Thin paper, which buckles and pushes the water into the hollows.
3. Too many pigments at once; three colours mixed on a wet sheet usually turn grey.

This kind of painting shows best on paper. Watercolours with nature motifs are in the watercolours gallery, and I wrote about how they look in a room in watercolours with flower motifs.