What it does
Draws masks on the selected layer. Choose the type from the flyout: Rectangle Mask, Ellipse Mask, Path Mask.
How to use it
- Select a layer — masks are drawn on the selected layer.
- Press M, or click the Mask button. Press M again to cycle mask types.
- Rectangle / Ellipse: drag. ⇧ and ⌥ work as in Shapes.
- Path: click to place points, drag to pull handles (⌥ breaks the tangent). Hover an existing mask to add a point (＋). Double-click or Enter to finish.
Options bar
| Name | What it does | Default/range |
|---|---|---|
| Shape | Rect, Ellipse or Path. | — |
| Op | Mask mode for the new mask: Add, Subtract, Difference, Invert. | Add |
Shortcuts
| Action | Mac | Windows/Linux |
|---|---|---|
| Mask tool / cycle type | M | M |
⇧M adds a marker, not the mask tool. In the After Effects keymap, M is unbound for this tool.