Other Masking Features

Frame Tool

Useful in an extremely limited set of circumstances, the Frame tool creates a Frame layer. If a document has only a Background and no other layer, this Frame layer will be empty. Otherwise, the topmost layer, whether selected or not, will be masked to the rectangle or ellipse drawn. You can also convert a vector shape into a frame with the same limitations. With a Frame layer highlighted, you may drag an asset from the Library panel, or choose File > Place Embedded… or Place Linked… to give the frame content or replace the content it had.

In each of those cases, the frame’s content is a Smart Object.

If your document has a number of layers, the Frame tool can be aggravating, as it may mask layers you’d wish it didn’t. If you need to mask a layer with an editable shape, use a vector mask.

Clipping Masks

This technique uses the visible extent of a layer, group, or Smart Object to control the visibility of other layers. So if a photo is clipped to a type layer, the photo is visible only where the type is. Each layer remains independently editable, so if the type changes, the visibility of the photo keeps up! There is also a bit of entanglement: the base layer controls the blending of all the layers in the clipping mask. So if the base layer’s opacity is lowered, the layers clipped to it also diminish. See “Blend Clipped Layers as Group” (page 205) to learn the intricacies of blending within clipping masks.

Note that a group can be used as the base “layer,” but cannot be clipped.

Knockout

This Advanced Blending Option allows the content of a layer, group, or Smart Object to act as a drill through layers below it. See “Knockout” (page 204) for an explanation.

Blend If

Another Advanced Blending Option. This one hides content based on the tone of the layer or those below it. See “Blend If” (page 208) to learn how this works.