How to apply a layer mask in Adobe Photoshop
Isha Misra wrote this article as part of their Bachelor of Architectural Design 3rd year elective, MADAboutMADA. In the elective, students are introduced to digital media and how it can be relevant to the architecture, design and art professions.
Masking layers can be particularly useful for architecture projects such as collages and editing renders. The tool allows you to hide parts of an image without having to delete it which gives you a lot more flexibility and confidence when using photoshop as you can make changes without having to reload the entire image.
What is a layer mask?
Applying masks to a layer is a reversible way to hide part of a layer. This method allows for more editing flexibility as opposed to permanently erasing or deleting part of a layer.
What you need to know:
Layer masks can be painted either black, white or grey and each colour has a particular function.
- BLACK to conceal: Adding black to a layer mask hides the layer that has the mask and shows what is in the layer below.
- WHITE to reveal: Adding white to a layer mask simply shows the layer with the mask.
- GREY is used for level of opacity: Adding different shades of grey results in varying opacity of the layer with the mask.
In this tutorial, we will learn how to create this image by applying layer masks.
Select the two images you want to mask and arrange them in two separate layers.
Select a layer in the Layers panel and click the ‘Add layer mask’ button at the bottom of the panel. A white layer mask thumbnail will appear on the selected layer, revealing everything on the selected layer.
Click on the layer with the tree and use the Magic Wand Tool to select the tree silhouette. There should be a dashed white line to indicate the selection.
Now, the aim is to replace the silhouette of the tree with the image of the earth, therefore the layer with the mask needs to be concealed. To do this click on the layer mask again and use the Paint Bucket Tool and paint the selection black. *Ensure that the FOREGROUND colour is BLACK.
You have successfully applied your first layer mask! The resulting image should look like this:
Save the image in .psd or .tiff format to retain the layers and layer mask for future editing.
The masking tool can be applied to many layers. Simply, create new layers and then use steps 1-4 to create you layer mask.