You can reuse masks in other layers and compositions—particularly Bezier masks you’ve spent a long time perfecting. Mask paths are stored inside a composition in a project file. It can be useful to create a project with compositions just for storing complex layer masks. When you want to use a mask from another project, import that project into your current project.
Copy, cut, duplicate, or paste a mask
Save a maskTo save an animated mask, select the mask keyframes you want to save.
To save a nonanimated mask, select the mask.
Reuse a mask
Delete masks