One of the first things you will want to master when you open up Photoshop is layer masks. When you first start to work with Photoshop you may find layer masks to be a little daunting. But, masks are a great tool to use to get your creative on!
Let’s get started with learning about this great little tool!
What Are Layer Masks?
Layer masks are an easy to overlay for a layer of your image. They can’t do much on their own. Everything that is done in Photoshop can be done nondestructively, and this is just one more thing that can help you work in this way. By setting a layer mask over your image you can wipe out some information on your image without touching the original layer or image. But a layer mask only effects the layer that it is overlaying.
The purpose of layer masks is to selectively control the visibility of portions of your image and that particular layer.
You use black and white values to color in the layer mask to set what you want it to cover. Black will cover and white will uncover. Grays will give you a degree of opacity.
In the example below I’ll show how you can take two pictures and put a layer over the top one.
Below, I’ve added a mask to the helmet and covered some of it up. You can see how the mask – the black and white picture – is painted to show only part of the helmet.
What About the Eraser Tool?
A lot of newcomers to Photoshop and digital art in general come into this and think that it’s easier to just use the eraser tool to get the result they want. That was me when I first started. I didn’t understand a lot of the tools or uses and masks literally terrified me because I just didn’t understand their purpose or use.
But, actually, it’s so much easier to use masks! If you make a mistake, sure, you can use the history in Photoshop to go back a few paces, but, that only goes back so far. If you made a lot of strokes or changes, it may not take you back all the way that you want to. And then your original is ruined.
Hence, working nondestructively. By using masks and layers and all sorts of other things within Photoshop, you are working nondestructively. That way, you can go back no matter how far back you want, and fix things, and change things until you get to the point where you want to be with your art.
I got frustrated so many times when I first started because I wasn’t working with masks or layers, for that matter and I didn’t know how to get back to where I wanted to be.
Yes, the eraser tool is very handy. Don’t not use it. But, be smart in using it. Myself as an artist, am lazy. I want the easy way around things and to still be able to get the great results.
Add Layer Masks to Your Image
So, how do we add a layer mask, you ask? Very easily.
On the bottom of your layers panel there is a row of icons.
Make sure you have a layer selected that you want to make adjustments to and add the layer mask to. Then pick the one that looks like a white rectangle with a hole in it. This is the icon you want when you add a layer mask to your image.
Click on that icon and the mask will pop up next to your layer you have selected. It will be white when it first comes up. By picking the opposite color that the mask is already – generally black – you can start painting in what you want to hide. To reveal more, you can paint in white.
Create Layer Mask From Transparency
You can create a layer mask from a transparency. If you have a png file:
You can create a transparency mask from this. Go to Layer>Layer Mask>From Transparency. This will automatically select all the pixels that exist and create a layer mask from this transparency.
As you can see from my example, all the little squares are hidden. That was the area that didn’t have pixel information. So the pixels were not selected for the mask. Instead, it selected the fish because that was the area with the pixel information.
There is another way to select all these pixels to create a layer mask from that selection. You could go to Select>Select All and that will select all of your pixels. To create a mask that will not cover up your image but cover all the area information around it, you would then go to Select>Inverse. Now press Alt + . This is the long way around, which, I admit, I was victim of this method for quite a while. It is a much longer way of getting the same, simple result.
Duplicate a Layer Mask
There will be times that you will want to duplicate layer masks. You may want to duplicate the same one on multiple layers. No worries. This process is easy enough to do.
Hold down ALT + click and drag the layer mask over to the layer you want to copy it to.
Move a Layer Mask
If you want to move a layer mask, it’s pretty much like any other program. Just click and drag the mask to the layer that you want it to go to.
View and Hide Layer Masks
In order to hide a layer mask, hold down the SHIFT key and left click the layer mask. This will show a large red X over top the layer mask.
Now, your mask is hidden. To unhide the mask just click on the mask.
To view your mask alone, click the ALT key and click the layer mask. This is a really helpful thing to do. Sometimes as I’m coloring in a layer mask, I miss spots. So, it’s good to pull this up on its own and double check these little holes and other things.
Unlink Layer Mask
To unlink a layer mask from a layer you will see a little chain link set between the layer image and the layer mask. Press and hold the ALT key while you click on the link. That will unlink the two items and will also return the link between the two items to get them linked again.
Delete a Layer Mask
To delete a layer mask you can just click and drag the layer mask to the garbage can down at the bottom right of your layers panel. Or while the layer mask is selected, click on the garbage can. It will ask you to confirm the deletion before it completes the action. So, you get a second chance to make sure you definitely want to do it. And, no worries, if you realize that you didn’t actually want it done you can click the undo right away.