I want to share my approach to painting clouds, which are one of the most practiced subjects in traditional painting schools and one of the most under-studied in digital art education.

Clouds are three-dimensional forms with volume — they're not flat shapes. They have a top lit by direct sun, sides that catch peripheral light, and a base that is in shadow and often reflects the ground color below.

The value structure: the top is the lightest area, the bottom is the darkest. The shadow on the bottom of a cumulus cloud on a sunny day is quite dark — often mid-grey. This contrast is what gives clouds their billowing, volumetric quality.

The color: clouds are white when lit by direct sun but the light that fills their shadows is sky blue. So the shadow areas of clouds are blue-grey, not grey. The temperature contrast between the warm lit top and the cool shadowed base is subtle but important.

The shape principle: cloud edges are harder on the lit top and softer on the shadow bottom, because the lit surface is a denser water droplet zone and the shadow falls into less dense vapor. Vary your edge quality to follow this logic.