As a Photoshop user, and even as a straight-up beginner, you’ll probably come across a time where you need to manipulate an image, working with transparency but not removing the pixels. If you’ve been too scared to work with Layer Masks before thinking they were too tricky, well, they really aren’t! What you need to know is the difference between black and white.
What Layer Masks do is they control the transparency of an image. But you might say that you can already do that by using the Opacity option on the selected layer. Well yeah, but that only lets you increase or decrease transparency of the entire layer. What if you want to have just one part fade out and into a gradient for example? Or what if you want to blend two images together without an awkward line in the middle?
After opening the images, they will be in separate windows. We will need them in the same window.
In order to bring one in the same window as the other, select the Move Tool, and simply drag one over the other.
Both images are in the same window. As you can see, the second one is on a different layer, on top of the first.
(You may need to adjust the background layer so that they don’t overlap too much. In order to make adjustments to the Background layer, it must first be unlocked. In order to do that, it has to be made into a layer. Simply double click the Background layer tab.)
Now that you have both images in the same window, you might think that you could just use the Eraser tool on a very soft setting in order to delete the line merging them together. Well, you could, but what if you later decide that you want to show more of the image? The only way to go back from here is to do it all over again, and that’s too tedious. Instead, let’s use a Layer Mask.
To create a Layer Mask, select the layer you want to apply the mask to (in this case, I selected the top layer), and click on the Layer Mask button. You won’t see any changes to your image, but instead you will see a layer mask thumbnail attached to your layer. You will see that it is filled in white. This is because in Layer Masks, white is transparent, black is opaque and grey controls the transparency levels.
In order to merge the two pictures together, we won’t be using the Eraser Tool, but the Paintbrush tool! Simply select your paintbrush tool, and set the foreground color to Black (remember, this will hide the pixels you don’t want showing). Make sure you have your Layer Mask thumbnail selected (not just the layer! You’ll only end up with a black streak on your picture), and paint over the area you want to hide!
As you can see, the Layer Mask isn’t fully white anymore. That’s because you’ve hidden some pixels. If you want to show more of the image, you can just go over it with white instead.
After messing around with it a bit more, this was the finished result. Probably not the best stock images to use, but you get the idea!
I hope you’ve learned something new today and have fun using non-destructive Layer Masks!