All About Grayscale Masks
Part 2: Masks vs. Selections - Differences and Similarities
How is a mask different from a selection?
Other than the way each of them is represented on the screen, there's really not a lot of difference between a mask and a selection.A mask is represented in shades of gray, or with a ruby overlay, but a selection is most often represented with a dashed line marquee. When you're talking about a selection, it's important to remember that the selected area is the part of the image that is unprotected. The areas outside of the selection are masked, or protected. So in a way, a selection is the exact inverse of a mask.
 An image with a selection. The selected area is inside the selection marquee. |
 The same selection displayed as a mask. The area covered by the ruby overlay is protected. |
Another difference between selections and masks is the way they are created. A selection is made by using any of the selection tools offered in your software (rectangular, elliptical, magic wand, lasso). A mask is created using the painting tools (any of the available brushes or a custom brush).
 To
the left is a custom brush. This brush was used to create the mask on the
right. The image on the far right has the mask applied to it. Using textured
and shaped brushes with masks, you can achieve a wide variety of unique
effects. |
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Your image editor will usually let you convert selections to masks and vice-versa. This is extremely useful! You can start out by making a selection with one of the selection tools, then you can convert that selection to a mask (to refine the selection using the painting tools), and then convert it back to a selection for further editing.
 Here's an image with a selection made using the magic wand tool. |
 Here the selection has been converted to a mask. |
 Using black paint, hidden portions of the image can be brought back into view. |
 Here the entire center of the flower has been "painted in" by working in mask mode. |
Visit the resources listed below for tutorials and information onr working with masks in various graphics software programs.
Related Resources:
- Masks in Adobe Photoshop
- Masks in Jasc Paint Shop Pro
- Masks in Corel Photo-Paint
- Free Grayscale Masks
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