Photoshop Layer Masking is a tool that feels really complicated at first, so many users avoid learning them. This tutorial aims to lower that barrier and make them more understandable while showing real world use cases to better show the power of this tool.
Jump to: Common Use Cases | Making Layer Masks | Modifying Layer Masks
What is a layer mask
A Layer Mask is like a window attached to a layer.
Layer Masks are black and white.
Black pixels in the mask will hide those pixels in their associated layer.
White pixels in the mask will reveal pixels in their associated layer.
Common Use Cases for Layer Masks
Color/Brightness adjustments
Often, the lighting in an image is such that you end up with areas of your image that are darker or have a different color tone than the rest of the image. Layer Masks on an adjustment layer allow us to apply that adjustment to certain areas of our image.
All Adjustment Layers automatically have an empty layer mask attached to them when they are created.
Scroll down to see more techniques for modifying layer masks.
Removing the background of an image in a non-destructive way
Non-Destructive Editing is often important for good file management. Layer Masks allows for an easy way to hide but not delete pixels in a layer.
Pixels hidden behind a mask are still safe in the document. The information is stored in the layer and can be easily revealed again by disabling or modifying the layer mask.
Adding a Layer Mask to a Layer
To apply a layer mask, select a layer in your Layers Panel, ensure that it isn’t locked, and click the small circle inside a rectangle icon at the bottom of the panel.
The new layer mask will always start empty, and not be hiding any pixels. You can switch between editing the pixels in the layer or the pixels in the mask by clicking on them. The selected object will have brackets surrounding it as shown below:
Modifying a Layer Mask
You can modify a layer mask in the same ways you edit a regular layer.
You can paint pixels using the brush tool, copy/paste vector graphics into the mask from another program or layer, use filters or render clouds directly on the mask.
Using the Brush Tool
Make sure that you have your mask selected. (There should be brackets around the mask and not the layer contents)
For most effects you’ll want a large soft brush for blending two layers together.
Add texture to the mask to create depth
Texture can also be quickly created or added using a solid color layer and a layer mask.
The example below was created by selected the layer mask, Filter > Render > Fibers in order to add texture into the layer mask and revealing the darker layer below.
Using vectors to create sharp lines in your layer mask
You can also use vectors to select specific areas of your document to add to the layer mask.
If you already have a vector shape you know you would like to use:
Copy/Paste the vector shape into your Photoshop document as a Smart Object
Once the Smart Object is placed in the document and positioned where you want to add it to your mask, hide the Smart Object Layer.
CTRL(or)CMD + Click on the Smart Object Layer preview to select that area of pixels.
Change your layer selection to the Layer Mask you would like to modify.
Fill your selection with either black or white to hide or reveal pixels attached to that mask.
Using the Pen Tool to create masks
When you activate your pen tool in Photoshop you are creating a “Path”. Once you create a path you can then open your Path Panel and Ctrl(or)CMD Click on the Path to select that area of pixels.
With the dancing ants of your pixel selection active, make sure you have the layer you want to attach a layer mask to selected in your Layers Panel.
Click the Mask button at the bottom of the Layers panel to create a new mask based on your pixel selection.
