A flat wash is a basic watercolor technique that you will use nearly every time you start a new painting. You usually use it when you need to cover a large area of your paper with paint. With the flat wash watercolor technique you end up with a flat or even area of color across the paper.

A flat wash is a watercolor technique used to create smooth and even areas of color, free from visible brushstrokes or variations in tone. This method is perfect for laying down solid backgrounds, filling in large areas, or creating a sense of unity in your artwork.

Flat washes are used to paint shapes of continuous color which have no variation in tone and hue. The appearance is uniform and “flat”. To execute a perfect flat wash with a wet on dry technique you need to paint in a fairly smooth, uninterrupted manner.

The watercolor technique Flat wash is a process for painting large, solid-color backgrounds or underpainting for glazing and for smaller areas and objects in a composition using the wet-on-wet technique.

To apply a flat wash, you need to dilute some color in water, then apply it uniformly to part of the composition (to paint a sky, for example) or to the whole sheet of paper (to create the background).