Creating channel masks
You can use the mouse, the New Channel Mask command, the
Transparency palette, or the Channels palette to make channel masks.
To create a channel mask
Do one of the following:
Option+double-click (Mac) or Ctrl+double-click (Windows)
the object to be masked. (If the object already has a channel
mask, Canvas places the channel mask in edit mode.)
Select the object to be masked and choose Object > Transpar-
ency > New Channel Mask.
Select the object to be masked. In the Transparency palette,
choose Channel in the Mask pop-up menu.
Canvas creates the channel mask and puts the new mask in edit
mode.
If the object is a paint object, Canvas creates a channel mask
with the same resolution as the paint object.
If the object is a vector, text, or group object, the New Mask
dialog box appears. Type the resolution you want for the
channel mask and click OK. Canvas creates the channel mask
with the specified resolution.
To use the Channels palette
You can create a channel mask for a paint object from an existing
alpha channel or color channel.
With a paint object in edit mode, drag an alpha channel into the chan-
nel mask slot in the Channels palette. If the slot already contains a
channel mask, the channel you drag there replaces the existing chan-
nel mask.
Editing channel masks
You can edit an objects channel mask to change the transparency
effects it produces. Generally, you can do anything that you can
when editing a color channel, alpha channel, or grayscale image: use
painting tools, filters, and image-adjustment commands, make selec-
tions, and paste selections into a channel mask.
To edit a channel mask
Do any of the following to place a channel mask in edit mode: