Mask

A shape that reveals part of a layer and hides the rest. Editing by what you allow to show, not what you erase.

A mask is selective permission: a shape that decides which parts of a layer may speak. Nothing is deleted; regions are silenced, revocably. Editing by inclusion rather than erasure is the deeper principle, and the reason complex composites stay reversible to the end.

In motion, the mask becomes choreography: edges tracked to a moving subject, reveals timed to a beat, light allowed through in the shape of a window. The craft concentrates at the edge itself, its softness, its wander, because the eye forgives an imperfect shape and never forgives an artificial edge.