How to Use Layer Masks in Photoshop

Layer masks are one of the most basic tools in Photoshop, and also one of the most important. They give you a completely non-destructive way to make part of a layer visible or invisible, which means you can cut subjects out of backgrounds, blend colors and textures together, and fade elements in and out without ever permanently deleting a single pixel. In this tutorial we’ll cover exactly how layer masks work, how to paint, invert, and duplicate them, and how to use them with adjustment layers and groups.

What Is a Layer Mask?

A layer mask is a way to make a layer either visible or invisible, and it works on regular layers, adjustment layers, fill layers, and even entire groups. The rule is simple: paint with black on a layer mask and that part of the layer becomes invisible, paint with white and it becomes visible again. Because the mask is separate from your actual layer content, you’re never destroying pixels, you’re only hiding or revealing them, which means you can change your mind at any point, even years later.

Layer Masks vs. the Eraser Tool

To see why layer masks matter, it helps to compare them to the Eraser Tool. If you fill a new layer with a color and then erase part of it away, that information is gone; the only way to get it back is to step backward through your History panel, which also undoes any other work you’ve done since. A layer mask solves this. Instead of erasing, you add a layer mask by clicking the layer mask icon at the bottom of the Layers panel, or by going to Layer > Layer Mask > Reveal All, which creates a mask that starts out entirely white. Grab the Brush Tool, set your foreground color to black, and paint over the area you want to hide. The layer content is still there underneath, completely intact, so if you ever want that area back, you simply switch your foreground color to white and paint over the same spot.

Creating and Painting a Layer Mask

Once a layer mask exists, you can control it with any tool capable of putting black or white pixels down, including the Brush Tool, the Marquee Tool combined with a fill, the Gradient Tool, or the Clone Stamp Tool. Click on the layer mask thumbnail in the Layers panel to make sure it’s selected and not the layer itself, then paint, fill, or select as needed.

Filling an Entire Layer Mask with Black or White

If you want to hide or reveal an entire layer at once rather than painting by hand, press Shift+Delete (Shift+Backspace on some keyboards) to open the Fill dialog, and choose Black to hide the whole layer or White to reveal it completely. This is the same Fill command used elsewhere in Photoshop, just applied to the mask instead of the layer content.

Useful Layer Mask Keyboard Shortcuts

1. Preview the mask (Alt/Option-click)

   Hold Alt (Option on Mac) and click the layer mask thumbnail to see a black-and-white preview of exactly what the mask looks like. Click again to return to the normal view.

2. Turn the mask into a selection (Ctrl/Cmd-click)

   Hold Ctrl (Cmd on Mac) and click the layer mask thumbnail to load its white areas as an active selection.

3. Temporarily disable the mask (Shift-click)

   Hold Shift and click the layer mask thumbnail to place a red X over it, temporarily disabling it so you can compare the layer with and without the mask applied.

4. Quick mask view (the slash key)

   With the layer selected, press the slash key, located just above the Return/Enter key, to see a quick mask overlay of the mask. Press it again to turn the overlay off.

Cutting a Subject Out with a Layer Mask

Layer masks really show their value once you use them with a selection tool to cut a subject out of its background. Since a layer mask can be built directly from any active selection, this turns selecting and masking into a single, easily reversible workflow.

Selecting Your Subject with the Magic Wand Tool

If your subject is shot on a clean, simple background, like plain white, the Magic Wand Tool makes quick work of the selection. Click on your subject’s layer, select the Magic Wand Tool, and click on the background around your subject. Hold Shift and click any remaining background areas the first click missed, such as small gaps near the arms or hair, to add them to the selection. Once your selection looks clean, click the layer mask icon at the bottom of the Layers panel to convert that selection directly into a mask.

Inverting a Layer Mask

Depending on which area you selected, your new mask might end up hiding your subject instead of the background. If that happens, click on the layer mask thumbnail and press Ctrl+I (Cmd+I on Mac) to invert it, swapping every black area to white and every white area to black. This flips which part of the layer is visible, and you can toggle it back and forth as needed while you check the result with an Alt/Option-click preview.

Using Layer Masks with Fill and Adjustment Layers

Layer masks aren’t limited to regular image layers, they work exactly the same way on fill layers and adjustment layers. Go to Layer > New Fill Layer > Solid Color to add a colored background behind your cut-out subject, then drag that new layer underneath your subject in the Layers panel. Double-click the color swatch at any time to change the fill color, and use the eyedropper in the color picker to sample a color directly from your own image if you want the background to complement your subject. If small holes remain in your cutout, click the fill layer’s mask, make a selection around each hole with the Marquee Tool, and fill it with black to close it up, exactly the same technique used on a normal layer mask.

Duplicating a Layer Mask Between Layers

Once you’ve spent time refining a mask, you don’t have to recreate it from scratch for a similar effect. Hold Alt (Option on Mac), then click and drag the layer mask thumbnail from one layer down onto another layer. You’ll see a small preview as you drag, and releasing the mouse copies the exact same mask onto the new layer. This is a great way to build offset color effects: duplicate your subject’s cutout mask onto a new solid color fill layer, nudge that new layer slightly to one side, and you get an interesting shadow or echo effect using the identical silhouette.

Using Layer Masks on Groups

Layer masks also work on entire groups, which is useful when you want one mask to control several layers at once. Select multiple layers in the Layers panel and press Ctrl+G (Cmd+G on Mac) to group them together, then click the layer mask icon while the group is selected to add a mask to the whole group. This is a good place to use the Gradient Tool: select a linear gradient set to foreground-to-transparent with black as your foreground color, then drag across the group’s mask to fade the entire group smoothly from invisible to visible, letting whatever is on the layer beneath show through gradually.

More Free Photoshop Tutorials

• Select Your Subject and Refine Edges in Photoshop
• Three Ways to Use Blend If
• Curves vs. Levels: Learn the Difference

Why This Approach Works

Layer masks work because they separate the decision of what’s visible from the pixels themselves. Painting black or white on a mask never touches your original layer content, so nothing is ever truly lost, which is exactly why it’s called non-destructive editing. That reversibility is what makes every other technique in this tutorial possible: you can build a selection into a mask, invert it if it comes out backward, disable it temporarily to compare before-and-after, and duplicate it onto other layers, all without redoing your original selection. The same logic extends to fill layers, adjustment layers, and groups, since a mask is really just an instruction for what to show and what to hide, and that instruction can sit on top of any kind of layer.

Final Thoughts

Layer masks are one of the most important tools you can learn in Photoshop, and once you get comfortable with them, you’ll find yourself reaching for one on nearly every image you edit. The core idea is simple: white reveals, black hides, and nothing is ever permanently destroyed. Start by practicing the basics, painting a mask by hand and toggling it with the keyboard shortcuts covered here, then move on to building masks from selections, duplicating them between layers, and applying them to groups for more advanced compositing work.