Layer masks and vector masks for non-destructive editing.
Layer Masks
A layer mask is a grayscale image attached to a layer that controls its transparency. White areas are fully visible, black areas are fully hidden, and gray areas are partially transparent.
Select the layer you want to mask.
Click the "Add Layer Mask" button at the bottom of the Layers panel.
A white (reveal all) mask is added. If you have a selection, the mask reveals only the selected area.
Paint on the mask with black to hide areas, white to reveal.
Painting on Masks
Click the mask thumbnail in the Layers panel to target the mask.
Use the Brush tool with black to hide, white to reveal.
Use gray values for partial transparency.
Press X to swap foreground/background and quickly switch between hiding and revealing.
Viewing the Mask
Alt+Click the mask thumbnail to view the mask as a grayscale image.
Shift+Click the mask thumbnail to temporarily disable the mask.
Click the layer thumbnail to return to editing the layer content.
Deleting Masks
Right-click the mask thumbnail.
Choose "Delete Layer Mask" to remove it entirely, or
"Apply Layer Mask" to permanently apply the mask to the layer pixels.
Disabling Masks
Temporarily disable a mask to see the full layer content without deleting the mask. The mask thumbnail shows a red X when disabled.
Vector Masks
Vector masks use path data (instead of pixel data) to define visibility. They produce clean, resolution-independent edges and are ideal for hard-edged shapes.
Create a path with the Pen tool or a shape tool.
With the path active, go to Layer → Vector Mask → Current Path.
The layer is clipped to the path shape.
Tip:A layer can have both a layer mask and a vector mask simultaneously. Both masks are combined multiplicatively.