Layer Mask in Photoshop
You can use masks to hide portions of a layer and reveal portions of the layers below.
Layer masks are grayscale bitmap images that are edited with the painting or selection tools. Layer masks are nondestructive, which means you can go back and re-edit the masks later without losing the pixels they hide. In the Layers palette, the layer masks appear as an additional thumbnail to the right of the layer thumbnail. This thumbnail represents the grayscale channel that is created when you add the layer mask.
The pure white areas in the mask represent the portions of your original image that will be 100% protected. The pure black portions of the image represent the areas of your original image that are completely masked out, or erased. The levels of gray in-between allow your image to be partially protected.
If you have trouble keeping track of which color does what, just think of masking tape to help you remember… masking tape is usually white or light colored, so the white areas of your mask are the most protected.
Layer masks can be used many different ways, here are some step by step tutorials…


Here are some step by step tutorials using the
I found a really good tutorial that takes us beyond just correcting for a red hue/tint on Smug Mug’s web site.
Getting Great Prints: Pleasing Skin Tones
Using masks is a powerful tool.
Practice, Practice, Practice