The airbrush is a magical brush that reaches its full potential when used in combination with the Slate. It is a 3D paint spray than can help colourizing a large surface without touching your paper.
Hover with your pen over the Slate's surface. The higher you are, the larger the spray area will be, indicated by the diameter of the cursor. Then simply click on one of the Slate's button to begin to spray and once again to stop it.

Did this answer your question?