Creating a Layer Mask

The creation of a layer mask requires two things: an open document and any Photoshop layer type with the exception of the Background. When you add the layer mask, you will be working with two layer elements—the image and the mask. It's important to know what element you're working on, or you might wind up painting on the image instead of the mask. When that occurs, it's good to remember the undo button. Once the mask is created, you can selectively control, without erasing, the visible portions of the image.