Quick Mask Mode
Remember when we were talking about the marching ants and how they can't accurately show you what a feathered selection looks like? Well, Quick Mask mode can show you what a feathered selection really looks like and can also help create basic selections. The quick-mask icon is located directly below the foreground and background colors in your Tools palette (Figure 2.94). When the left icon is turned on, you are in Standard mode, which means you create selections using the normal selection tools, and they will show up as the familiar marching ants. The right icon enables Quick Mask mode, and that's where selections will show up as a translucent color overlay.
Figure 2.94. The quick-mask icons.
To see how it works, first make a selection using the Marquee tool, and then turn on Quick Mask mode by clicking on the right icon under the foreground and background colors (or just type Q to do the same thing). In Quick Mask mode, the selected area should look normal and all the nonselected areas should be covered with a translucent color (Figures 2.95 and 2.96).
Figure 2.95. A selection shown in Standard mode. (©2005 Stockbyte, www.stockbyte.com)
Figure 2.96. The same selection shown in Quick Mask mode.
Now that you're in Quick Mask mode, you no longer need to use selection tools to modify a selection. Instead, you use standard painting tools and paint with black to take away from the selection, or white to add to it. When you're done modifying the selection, switch back to Standard mode and you'll be back to marching ants (Figures 2.97 and 2.98).
Figure 2.97. A selection modified in Quick Mask mode.
Figure 2.98. End result after switching back to Standard mode.
Now let's see what feathered selections look like in Quick Mask mode. Make another selection using the Marquee tool. Next, choose Select > Feather with a setting of 10, and then switch to Quick Mask mode and take a look (Figures 2.99 and 2.100). Feathered selections appear with blurry edges in Quick Mask mode. This happens because partially transparent areas (that is, ones that are more transparent than the rest of the mask) indicate areas that are partially selected (50% transparent means 50% selected).
Figure 2.99. Normal. (©2005 Stockbyte www.stockbyte.com)
Figure 2.100. Feathered.
The confusing part about this process is that when you look at the marching ants that appear after you switch back to Standard mode, they only show you where the selection is at least 50% selected. That isn't a very accurate picture of what it really looks like (Figure 2.101). But in Quick Mask mode, you can see exactly what is happening on the image's edge. So, if you want to create a feathered selection in Quick Mask mode, just choose a soft-edged brush to paint with. Or, if you already have a shape defined, choose Filter > Blur > Gaussian Blur, which will give you the same result of feathering but will show you a visual preview of the edge.
Figure 2.101. The marching ants show up where an area is at least 50% selected.
