If you've been using Photoshop for a while, you've probably run into moments where you want to color inside a shape without spilling over the edges, or hide part of a layer without deleting anything permanently. Alpha Lock, Layer Masks, and Clipping Masks all solve versions of that problem — but in different ways. Here's a breakdown of when to use each one.

Alpha Lock

Alpha Lock (also called Transparency Lock) keeps your brush strokes confined to the already-painted areas of a layer. Think of it like coloring inside the lines — anything transparent stays transparent, no matter where you paint.

How to turn it on

1. Select your layer in the Layers panel.
2. Click the checkerboard icon at the top of the Layers panel to lock transparent pixels.
3. Paint freely — only the opaque parts of the layer will pick up color.

Shortcut: Press / (forward slash) with the layer selected.

You can also Cmd + click the layer thumbnail to select its contents (you'll see marching ants appear).

Best for

• Adding shading or texture to an icon or logo without worrying about edges.
• Quick color adjustments to a flat shape.

Worth knowing

Alpha Lock is fast and simple, but it's destructive — meaning your changes are baked into the layer. If you think you might want to adjust the mask later, a Layer Mask gives you more flexibility.

Layer Masks

Layer Masks are the non-destructive way to hide parts of a layer. Instead of erasing pixels, you paint on a separate mask — black hides, white reveals, and grey gives you partial transparency. The original layer is always intact underneath.

How to add one

1. Select the layer you want to mask.
2. Click the 'Add Layer Mask' icon at the bottom of the Layers panel (it looks like a rectangle with a circle inside).
3. Paint on the mask with black to hide areas, white to bring them back.

Best for

• Blending two photos together seamlessly.
• Any situation where you might want to change your mind later.
• Complex compositing where precision matters.

Worth knowing

Layer masks have a bit of a learning curve if you're new to the black/white logic, but once it clicks it becomes second nature. They're worth learning early — most professional Photoshop work relies on them heavily.

Clipping Masks

A Clipping Mask uses one layer to control the visibility of the layer above it. Whatever shape the bottom layer is, the top layer clips to it. It's the go-to technique for adding texture or color to a specific shape without leaving your original layer.

How to set one up

1. Place the layer you want to clip directly above the base layer (the one whose shape you want to use).
2. Right-click the top layer and select Create Clipping Mask. You'll see a small arrow appear indicating it's clipped.

Best for

• Dropping a texture into a shape or letter.
• Applying color fills or adjustments to one specific element without affecting everything else.

Worth knowing

If you move or reshape the base layer, the clipped layer moves with it — which is usually exactly what you want, but good to keep in mind in complex files.

Quick comparison

• Alpha Lock — fast, simple, permanent. Good for quick texture or shading work.
• Layer Masks — flexible, non-destructive, powerful. Best for anything you might want to refine.
• Clipping Masks — clean, intuitive, great for texturing shapes. Easy to adjust without breaking anything.

All three are worth having in your regular toolkit. If you want to go deeper on how these same concepts work in Procreate, check out the companion post: Alpha Lock, Clipping Mask & Layer Mask in Procreate and Photoshop.