Photoshop: Layer Mask Cutouts
If you’ve ever worked in Photoshop, you’ve undoubtedly experienced that sinking feeling that occurs after you’ve completed a cutout, realizing too late that you’ve accidentally erased a part of the picture that should’ve remained.
There are many ways to avoid this problem when doing cutouts. This tutorial is going to focus on using layer masks to erase, but the overall theory revolves around protecting your original image. The least amount of destruction that an image goes through the better.
Using layer masks to erase in Photoshop doesn’t actually remove any part of the image – it hides the part that you don’t want visible.
Let’s take this picture of the St. Louis Arch against a cloudy sky background. Begin by selecting the background. There are many ways to do this but we’ll leave those for another tutorial.
Now we have to change the selection from the background to the arch, so inverse your selection (Select > Inverse or ctrl-shift-I). The “marching ants” should now encircle the arch. Then press the Add Layer Mask button on the Layers palette, which will apply a layer mask to the current layer.
Your layer palette should now show a layer mask applied.
With layer masks, black is hidden while white is visible.
What’s nice about this tactic is that the background is still there. The layer mask is just hiding the area that’s colored black. If you want to show any part of the background or if you noticed an error in your cutout, simply grab your paintbrush, make white your foreground color, and paint in the area that you want visible on your layer mask.
