To use Quick Mask mode to create and edit selections quickly, start with a selection and then add to or subtract from it to make the mask. You can also create the mask entirely in Quick Mask mode. Color differentiates the protected and unprotected areas. When you leave Quick Mask mode, the unprotected areas become a selection.
A temporary Quick Mask channel appears in the Channels panel while you work in Quick Mask mode. However, you do all mask editing in the image window.
A color overlay (similar to a rubylith) covers and protects the area outside the selection. Selected areas are left unprotected by this mask. By default, Quick Mask mode colors the protected area using a red, 50% opaque overlay.
A. Standard mode B. Quick Mask mode C. Selected pixels appear as white in channel thumbnail D. Rubylith overlay protects area outside selection, and unselected pixels appear as black in channel thumbnail
Paint with white to select more of an image (the color overlay is removed from areas painted with white). To deselect areas, paint over them with black (the color overlay covers areas painted with black). Painting with gray or another color creates a semitransparent area, useful for feathering or anti-aliased effects. (Semitransparent areas may not appear to be selected when you exit Quick Mask mode, but they are.)
A. Original selection and Quick Mask mode with green chosen as mask color B. Painting with white in Quick Mask mode adds to the selection C. Painting with black in Quick Mask mode subtracts from the selection
If a feathered mask is converted to a selection, the boundary line runs halfway between the black pixels and the white pixels of the mask gradient. The selection boundary indicates the transition between pixels that are less than 50% selected and those that are more than 50% selected.
Choose Select > Deselect to deselect the selection.
You can convert this temporary mask to a permanent alpha channel by switching to standard mode and choosing Select > Save Selection.
Sets masked areas to black (opaque) and selected areas to white (transparent). Painting with black increases the masked area; painting with white increases the selected area. When this option is selected, the Quick Mask button in the toolbox becomes a white circle on a gray background .
Sets masked areas to white (transparent) and selected areas to black (opaque). Painting with white increases the masked area; painting with black increases the selected area. When this option is selected, the Quick Mask button in the toolbox becomes a gray circle on a white background .
To toggle between the Masked Areas and Selected Areas options for quick masks, Alt-click (Windows) or Option-click (Mac OS) the Quick Mask Mode button.
Both the color and opacity settings affect only the appearance of the mask and have no effect on how underlying areas are protected. Changing these settings may make the mask more easily visible against the colors in the image.