How to invert a layer mask in Adobe Photoshop.

Layer masks are effective for hiding and showing different parts of an image. Invert them to instantly work with the unmasked area rather than the masked area — simply press Command+I on Mac or Ctrl+I on Windows. 

You may find it easier to mask the area you don’t want to edit rather than the area you do. Inverting a mask is simple and gives you plenty of opportunities to experiment along the way. Use inverted layer masks for dozens of different projects, whether you’re refining hair or trying to remove a background.

When you use the Brush tool in tandem with masking, painting white will reveal your adjustments or add to your mask, while black areas will conceal your adjustments or subtract from your mask. With this technique, you can fine-tune masks across layers for precise and consistent edits that you can easily undo if necessary.

Layer masks (which are pixel-based and can have feathered edges) and vector masks (which are shape-based and have sharp edges) work with all the Photoshop tools you might already be familiar with — including the Brush tool, the Pen tool, the Gradient tool, the Eraser tool, and more.

Sharp and jagged edges, whether they’re from pixelation, aliasing, or another issue, can often be difficult to fix. Using layer masks, you can apply blurs and gradients to smooth the severe edges.

To blend one image or solid color into another, apply a layer mask to the image or solid fill layer that’s on the top. Invert that layer mask by hitting Command+I on Mac or Ctrl+I on Windows. Then, with your layer mask selected and white set as your foreground color, paint into your layer mask with the Gradient tool to allow the top image to blend into the bottom one.

You can use Smart Filters and layer masks at the same time, to add, remove, and preview different effects quickly without changing the underlying image.