How to Use a Layer Mask in Photoshop

Using a Layer Mask in Photoshop

When I first dove into the magical world of Photoshop, I was very intimidated.  In fact, I became overwhelmed when I started exploring all of the buttons and options.  For this reason, I would open the software and then close it a few minutes a few minutes later, convinced that I would never be able to learn enough to create professional edits and composites.

Finally, I devoted a few days to study, practice, research, watch videos, and teach myself as much as possible.  One of the first and most important things I familiarized myself with, was a Photoshop layer mask!

What is a Layer Mask?

A layer mask is a tool that gives you control of each layer you are working with.  It allows you to take a single layer and modify specific areas of the image, rather than global changes on the entire layer (If you don't know what a layer is, you may want to read our tutorial on Photoshop layers before learning about layer masks).

Let's say you open a new layer to adjust brightness or exposure on your image.  Maybe you need to bump up the exposure a few stops only on your subject's face?  Or maybe you ran a Photoshop action but only want it to affect only certain areas of your image?  A layer mask gives you the flexibility to do this.

How To Use a Photoshop Layer Mask

First, open the image you are working with in Photoshop.  For this basic tutorial, I'm using a stock image from Pexels.

Once you have the image opened, create a new fill adjustment layer.  This can be done by clicking on the half filled circle located at the bottom of your layers panel, as shown circled in red below.

Once you click on the fill/adjustment layer drop-down arrow, you will get a window of adjustment options to choose from.

For this basic tutorial I'm going to do an exposure adjustment layer.  Keep in mind this is the actual layer, NOT a layer mask, therefore the adjustment will affect the entire image.  For this demonstration, I bumped the exposure up to around +2 so that the changes would be very evident.  Notice the entire image is much brighter now.

Now I am going to create a layer mask, so that I can remove the exposure change from a select part of the image.  To do this, first make sure the layer you are working on is highlighted in blue, then click on the rectangle icon at the bottom of the layers panel (I've circled this in red below).

Once you click on the layer mask icon, you will see there is now a white box in the exposure layer.  A key phrase to keep in mind when working with layer masks is "white reveals, black conceals".

Since our layer mask is white, this means the adjustment is revealed/showing on the image we are working with.  You can invert the layer to make it black to conceal/hide the adjustment as well - which would mean instead of taking away parts of the adjusment, we would be painting on the adjustment.

To keep this simple, we are going to leave our white layer mask as it - concealing the exposure adjustment we just made.

Now lets “brush away”, or remove, some of the exposure from half of the image, just to see how it works.  To do this, select the brush tool from the toolbar, leaving opacity at 100% just to get the full effect.  Remember, we are wanting to conceal/hide/erase the adjustment from part of the image, so we'll need a black brush.

Now that we have our white layer mask and black brush ready to go, we can paint/erase over the areas we want to remove the adjustment from.  As mentioned earlier, I'm leaving my brush opacity at 100% just so that the changes are clearly visible.

Once you become more familiar with layer masks, you can play around with adjusting the opacity of the brush to choose to what degree you want to conceal/hide.  If my opacity was set to 10%, the changes would be much more subtle.

As you can see below, working at 100% opacity with my brush, I have completely removed the exposure adjustment over the right half of my image by brushing over the area.

You will also notice that the white layer mask in the adjustment layer is now half black, showing where we hid the adjustments.  If you want to bring part of the exposure back in that area, just switch your brush from black to white and paint the adjustment back in.  Remember "white reveals, black conceals"!

Layer masks can be used on action layers as well.  They also work great for in-depth photo manipulations.  Learning to use this simple tool will get you well on your way to mastering the basic fundamentals of Photoshop.

Do you have any questions or comments about Photoshop Layer Masks?  Leave us a comment below - we would LOVE to hear from you!  And PLEASE SHARE our tutorial using the social sharing buttons (we really appreciate it)!