Layer masks explained: edit without deleting anything
A layer mask is a grayscale picture attached to a layer. Where the mask is white the layer is visible, where it is black the layer is hidden, and gray values are partly transparent. Because nothing is deleted, you can change your mind at any time.
Add a mask
Select the layer and choose Layer → Layer mask → Reveal all, or click the mask button at the bottom of the Layers panel. A white thumbnail appears next to the layer thumbnail. To start with the layer hidden instead, choose Hide all. If you already have a selection, Reveal selection creates a mask from it.
Paint on the mask
With the mask thumbnail selected, any brush paints on the mask instead of on the picture. Painting black hides, and painting white reveals. The foreground color decides which: a dark color hides, a light color reveals. Press X to swap black and white while you paint. A soft brush gives smooth edges, and a hard brush gives sharp ones.
Blend two photos
- Open the first photo, then place the second one as a new layer above it.
- Add a mask to the top layer using Reveal all.
- Choose the Gradient tool, set it to black-to-white and drag across the area where the photos should fade into each other.
- Refine the transition with a soft brush.
Useful mask commands
- Disable mask: temporarily shows the layer without the mask so you can compare.
- Apply mask: bakes the mask into the layer pixels and removes the mask. This cannot be edited later, although you can undo it.
- Delete mask: removes the mask and shows the layer completely.
- Clipping mask: Layer → Clipping mask limits a layer to the shape of the layer below, which is handy for putting a texture inside a shape.
Common problems
If painting appears to do nothing, check that the mask thumbnail, not the picture thumbnail, has the highlighted frame. If the whole layer disappeared, the mask was probably created with Hide all or you painted black over everything; press Ctrl Z or fill the mask with white.
More guides
- How to correct the colors and brightness of a photoFix dull, dark or color-cast photos with levels, curves and hue/saturation, using adjustment layers you can change later.
- Opening and saving PSD files in the browserHow PSD files are handled: which layers, masks and effects are kept, what the “flattened” option means, and tips for saving.
- Which selection tool should you use?Rectangle, ellipse, lasso, polygonal lasso, magic wand and color range compared, with tips for clean selection edges.
- Retouching: remove blemishes and unwanted objectsUse the spot healing brush, healing brush and clone stamp to remove spots, dust and small objects from a photo without leaving obvious traces.