Color Wise Mask

Masks in image editing software are a way of protecting specific areas of an image, just as we would use masking tape when painting our house. A mask consists of a grayscale channel, called an alpha channel and is often displayed as a ruby overlay so the underlying image can be seen through the mask. The darkest areas of a mask are the areas most protected and the white areas are unprotected. Shades of gray represent areas of partial protection that corresponds with the level of gray.