Adobe® Photoshop® 7.0 Classroom in a Book®

Creating a mask

gradient In addition to using black to indicate what’s hidden and white to indicate what’s selected, you can paint with shades of gray to indicate partial transparency. For example, if you paint in a channel with a shade of gray that is at least halfway between white and black, the underlying image becomes partially (50% or more) visible.

You’ll experiment by adding a gradient (which makes a transition from black to gray to white) to a channel and then filling the selection with a color to see how the transparency levels of the black, gray, and white in the gradient affect the image.

1.	In the Channels palette, create a new channel by clicking the New Channel button () at the bottom of the palette. The new channel, labeled Alpha ...