Viewing layer masks as grayscale images
You can also view a layer mask as a grayscale image.
To view a layer mask as a grayscale image
1
Select a layer with a layer mask.
2
In the
Channels panel, click the layer mask.
In this mode, the RGB image is hidden.
To hide the layer mask, click the eye icon

next to the layer mask, so that the icon changes to a closed eye

.