The
command allows you to temporarily disable the effect of the selected layer masks. A red border will be shown around the thumbnail of the selected layer masks in the Layers Dialog. To enable the layer masks use the same command again.You can access this command
From the main menu through
→ → .From the Layers Dialog, you can access it through the command of its context menu; or by holding down the Ctrl+Alt keys and clicking on the layer mask's thumbnail in the Layers Dialog.