The command lets you see the
layer mask better by turning the image invisible. When you click on the
menu entry, a check is displayed next to it and the layer mask's
thumbnail in the Layers Dialog is shown with a green border. The layer
itself is not modified; you can turn it visible again later.
Activating the Command
You can access this command from the image menubar through
→ → ,
or by holding down the Alt key
on some systems) and single-clicking on the layer mask's
thumbnail in the Layers Dialog.
You can undo this action by unchecking the menu entry in the
submenu or by Alt-clicking (or
Ctrl+Alt-clicking) again on the layer mask's thumbnail.