How do I apply a Mask?

To use the masking feature, follow these steps:

1. Select the element you want to mask. Any overlay (effect, photo, video, or text) on the timeline can be masked. Overlays are typically found on the top track of the timeline. To learn how to overlay photos or videos, refer to How can I create an overlay (picture-in-picture or layering)?.
2. Choose Mask from the bottom toolbar, and select your preferred shape. Depending on the shape selected, part of your overlay is now included in the mask.
3. You can resize the mask on the preview (using a pinching gesture) to include a larger or smaller portion of your overlay. Drag the mask on the preview to reposition it.

To exclude the part of the overlay that the mask covers, select Invert to the right of the Mask tab.

Pro tip: To feather your mask (meaning, to soften its edges), drag the yellow arrowhead away from the masked element.