Adobe Photoshop CS4 - Manual (Page 285)

278 USING PHOTOSHOP CS4
Selecting and masking
Last updated 1/10/2010
Spot Color Converts an alpha channel to a spot color channel. Only available for existing channels.
Color Sets the color and opacity of the mask. Click the color field to change the color. 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.
Paint on a channel to mask image areas
When the new channel appears at the bottom of the Channels panel, it is the only channel visible in the image window.
Click the eye icon
for the composite color channel (RGB, CMYK) to display the image with a color overlay showing
the mask.
❖ Select the brush or an editing tool and do one of the following to add or subtract from the mask created from the
alpha channel:
• To remove areas in the new channel, paint with white.
• To add areas in the new channel, paint with black.
• To add or remove areas using opacities less than 100%, set the Opacity in the options bar of the painting or editing
tool and then paint with white or black. You can also paint with a color to achieve lower opacities.
Save and load selections
You can save any selection as a mask in a new or existing alpha channel and later reload the selection from the mask.
You can use a selection as a layer mask by loading the selection to make it active, then adding a new layer mask.
More Help topics
“ Add layer masks ” on page 325
Save a selection to a new channel
1 Select the area or areas of the image you want to isolate.
2 Click the Save Selection button at the bottom of the Channels panel. A new channel appears, named according
to the sequence in which it was created.
Save a selection to a new or existing channel
1 Use a selection tool to select the area or areas of the image you want to isolate.
2 Choose Select > Save Selection.
3 Specify the following in the Save Selection dialog box, and click OK:
Document Chooses a destination image for the selection. By default, the selection is placed in a channel in your active
image. You can choose to save the selection to a channel in another open image with the same pixel dimensions or to
a new image.
Channel Chooses a destination channel for the selection. By default, the selection is saved in a new channel. You can
choose to save the selection to any existing channel in the selected image or to a layer mask if the image contains layers.
4 If you’re saving the selection as a new channel, type a name for the channel in the Name text box.
5 If you’re saving the selection to an existing channel, select how to combine the selections:
Replace Channel Replaces the current selection in the channel.
Add to Channel Adds the selection to the current channel contents.