How does layer mask work

Skip to content Skip to navigation. More News. Monash team designing self-screening security portal for airports globally. Monash Design staff and students sweep Good Design Awards. Select the two images you want to mask and arrange them in two separate layers. You have successfully applied your first layer mask! The resulting image should look like this:. After you create a layer with a vector mask, you can apply one or more layer styles to it, edit them if needed, and instantly have a usable button, panel, or other web-design element.

The Properties panel provides additional controls to adjust a mask. You can change the opacity of a mask to let more or less of the masked content show through, invert the mask, or refine the mask borders, as with a selection area. When you add a layer mask, you can hide or show all of the layer, or base the mask on a selection or transparency.

Photoshop converts transparency into an opaque color, hidden by the newly created mask. The opaque color varies greatly, depending upon the filters and other processing previously applied to the layer. This technique is helpful for video and 3D workflows. By default, a layer or group is linked to its layer mask or vector mask, as indicated by the link icon between the thumbnails in the Layers panel. The layer and its mask move together in the image when you move either one with the Move tool.

To reestablish the link between a layer and its mask, click between the layer and mask path thumbnails in the Layers panel. Layer masks are stored as alpha channels, so applying and deleting layer masks can help reduce file size.

You can also delete a layer mask without applying the changes. For easier editing of a layer mask, you can display the grayscale mask by itself or as a rubylith overlay on the layer. Both the color and opacity settings affect only the appearance of the mask and have no effect on how underlying areas are protected. For example, you may want to change these settings to make the mask more easily visible against the colors in the image. Use the Properties panel to adjust the opacity of a selected layer or vector mask.

The Density slider controls mask opacity. Feather lets you soften mask edges. Other options are specific to layer masks. The Invert option reverses masked and unmasked areas. For information on the Color Range option, see Create and confine adjustment and fill layers. As you lower the density, more of the area under the mask becomes visible.

Feathering blurs the edges of the mask to create a softer transition between the masked and unmasked areas. Feathering is applied from the edges of the mask outward, within the range of pixels you set with the slider. Click Select and Mask in the options bar. You can modify mask edges with the options in the Select and Mask workspace and view the mask against different backgrounds. Buy Adobe Photoshop or start a Free Trial.

Legal Notices Online Privacy Policy. Buy now. That's actually a very common thing to do with a layer in Photoshop, allowing you to fade from one image to another. But you can't do that with the Opacity option since as I said, it's limited to controlling the transparency of the entire layer at once. What you would need is some way to control the transparency of different areas of the layer separately.

What you would need is a layer mask. Shortcodes, Actions and Filters Plugin: Error in shortcode [ ads-basics-middle-2 ]. Let's look at an example. Here I have a couple of wedding photos that I think would work well blended together. Here's the first one:. In order to blend them together, whether I'll be using a layer mask or not, I need to have both photos inside the same Photoshop document, so with each photo open in its own separate document window, I'm simply going to press V on my keyboard to select my Move Tool and then click inside one of the documents and drag that photo into the document containing the other photo:.

Now both photos are in the same Photoshop document, and if we look in the Layers palette, we can see that each one is on its own separate layer, with the photo of the couple facing towards the camera on top and the photo of the couple walking away from us into the woods below it:. So far, so good. Now, how am I going to blend these two photos together? Well, let's see what happens if I simply try lowering the opacity of the top layer. After lowering the opacity of the top layer which again contains the image of the couple facing towards the camera on the right , the image on the bottom layer of the couple walking in the woods is now showing through the image above it.

Let's try something else. Shortcodes, Actions and Filters Plugin: Error in shortcode [ ads-basics-middle-float ]. So far in our quest to blend our two photos together, we've tried lowering the opacity of the top layer with disappointing results, since all that basically did was fade the entire image.

What I really want is for the couple in both images to remain fully visible, with the blending of the two images happening in the area between the bride walking away from us on the left and her looking towards us on the right.

I know, why don't I just use Photoshop's Eraser Tool! That's what I'll do. I'll use the Eraser Tool with nice, soft edges to erase the part of the image on the right that I don't need. Yep, this should work. I'll press E on my keyboard to quickly select the Eraser Tool. As I said, I want soft edges for my Eraser, so I'm going to hold down my Shift key and press the left bracket key a few times, which softens the edges.

I can also increase or decrease the size of the Eraser as needed using the left bracket key on its own to make the Eraser smaller and the right bracket key to make it larger the same keyboard shortcut works with any of Photoshop's brush tools.

And now that I have my Eraser at the right size and with soft edges, I'll go ahead and erase away parts of the left side of the top image so that it blends in with the image below it:. Things definitely look much better now than they did when we tried lowering the opacity of the top layer. The couple is still visible in both images with a nice transition area in the middle, which is what I wanted. The Eraser Tool worked great! Who needs layer masks!

I'm happy with this, I think my client is going to be happy with this as well, so I'll email a copy of the image off to my client, save my Photoshop document, close out of it, shut down my computer and go enjoy the rest of my day while I wait for the client to call me and tell me how awesome I am.

A couple of hours later, the phone rings and it's my client. They like the image overall, but they think I've removed too much of the bride's veil from the photo on the right and they'd like me to bring some of it back into the image, at which point they'll be happy to pay me for my work.

I head back to my computer, open my Photoshop document back up, and all I need to do now is bring back some of the bride's veil on the right by Simple answer? I can't. Not without doing the whole thing over again, anyway, which would be my only option in this case.

There's nothing else I can do here because I've erased that part of the image and when you erase something in Photoshop, it's gone for good. If I look in the top layer's preview thumbnail in the Layers palette, I can see that I have in fact erased that part of the image:. And if I click on the eyeball icon to the left of the bottom layer to temporarily turn it off, leaving only the top layer visible in my document, it's very easy to see that the section I erased from the left of the top image is now completely gone:.

The checkerboard pattern in the image above is how Photoshop represents transparency in an image, as in there's nothing there anymore. As in I've messed up and now I have to do the work all over again from the beginning.

Stupid Eraser Tool. So now what? I've tried lowering the opacity of the top layer and that didn't really work. I've tried erasing parts of the top image away with the Eraser Tool and while that did work, I ended up permanently deleting that part of the image and now if I need to bring some of it back, I can't. I guess all I can really do then is set the number of undo's in Photoshop's Preferences to and never close out of my Photoshop documents until after the client has paid me. What about these layer masks I keep hearing so much about?

Would they work out any better? Let's find out! The Opacity option left us disappointed. The Eraser Tool did the job but also caused permanent damage to our image. Wouldn't it be great if we could get the same results we saw with the Eraser Tool but without the "permanent damage to our image" part?

Well guess what? We can! Say hello to Photoshop's layer masks. As I mentioned at the beginning of this discussion, layer masks allow us to control the transparency of a layer, but unlike the Opacity option which controls overall transparency, layer masks allow us to set different levels of transparency for different areas of the layer although technically, you could use them to control the overall opacity as well, but the Opacity option already handles that very well and layer masks are capable of so much more.

How do layer masks work? Well rather than talking about it, let's just go ahead and use one to see it in action. Before we can use a layer mask though, we first need to add one, since layers don't automatically come with layer masks. To add a layer mask, you first want to make sure that the layer you're adding it to is selected in the Layers palette the currently selected layer is highlighted in blue , otherwise you'll end up adding it to the wrong layer.