Creating alpha channels (Photoshop)

You can create a new alpha channel and then use painting tools, editing tools, and filters to add the mask to it.

To create an alpha channel using current options:

1. Click the New Channel button at the bottom of the Channels palette. The new channel is named according to the sequence in which it was created.
2. Use a painting or editing tool to paint in the image. Paint with black to add to the channel; paint with white to remove from the channel; paint with a lower opacity or a color to add to the channel with lower opacities.

To create an alpha channel and specify options:

1. Do one of the following:
• Alt-click (Windows) or Option-click (Mac OS) the New Channel button at the bottom of the palette.
• Choose New Channel from the Channels palette menu.
2. Type a name for the channel.
3. Select display options for the channel, as described in steps 2 through 4 of the procedure for changing Quick Mask options in Using Quick Mask mode to make selections (Photoshop). Alpha channel options are identical to Quick Mask options.
4. Click OK. A new channel appears at the bottom of the Channels palette and is the only channel visible in the image window.
5. Click the eye icon next to a color channel or the composite color channel to display the image with a color overlay.
6. Use a painting or editing tool to paint in the image. Paint with black to add to the new channel, paint with white to remove from the new channel, or paint with a lower opacity or a color to add to the new channel with lower opacities.