Using Quick Mask Mode - Adobe PHOTOSHOP 5.0 User Manual

250 CHAPTER 10
Using Channels and Masks
In addition, masks let you save and reuse time-
consuming selections as alpha channels. (Alpha
channels can be converted to selections and then
used for image editing.) Because masks are stored
as 8-bit grayscale channels, you can refine and
edit them using the full array of painting and
editing tools.
When a mask channel is selected in the Channels
palette, foreground and background colors appear
as grayscale values. (See "Using Quick Mask
mode" on page 250.)
A. Opaque mask used to protect the background and color the
shell. B. Opaque mask used to protect the shell and color the
background. C. Semitransparent mask used to color the back-
ground and part of the shell.
In Photoshop, you can create masks, all stored
at least temporarily as grayscale channels, in
three ways:
Quick Mask mode lets you create and view a
•
temporary mask for an image (see "Using Quick
Mask mode" on page 250).
Alpha channels let you save and load a selection
•
to be used as a mask (see "Using alpha channels"
on page 252).
A
B
Layer masks let you create a mask for a specific
•
layer (see "Using layer masks" on page 276).

Using Quick Mask mode

Quick Mask mode lets you edit any selection as a
mask without using the Channels palette and
while viewing your image. The advantage of
editing your selection as a mask is that you can use
almost any Photoshop tool or filter to modify the
mask. For example, if you create a rectangular
selection with the marquee tool, you can enter
Quick Mask mode and use the paintbrush to
extend or contract the selection, or use a filter to
distort the edges of the selection. You can also use
selection tools, because the quick mask is not a
selection.
C
Start with a selected area and use Quick Mask
mode to add to or subtract from it to make the
mask, or 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 palette while you work in Quick Mask
mode. However, you do all mask editing in the
image window.
To create a quick mask:
1 Using any selection tool, select the part of the
image you want to change.
2 Click the Quick Mask mode button (
toolbox.
For a color illustration of Quick Mask
mode, see figure 10-1 on page 227.
) in the