Photoshop 101 – Working With Alpha Channels

August 17, 2009 • By

Alpha channels are one of those features in Photoshop that you don’t normally find  until someone shows you.  In this tutorial we will be loading and saving selections in an alpha channel as well as adding some highlights to an image.

Today we will be working with this lovely image of a chihuahua with a mohawk from iStockphoto:

Saving a selection in an alpha channel

1 Select the area that you want to remove via the pen tool, marquee tool or magic wand.

2 Go to select>save selection. Select new channel from the pop up and name the channel

Head over to your channel palette and click on the new alpha channel ‘dog’.

You can then utilize the alpha channel for later selections by command clicking on the channel thumbnail image.

Transparent Highlights

1 Go into the chanel pallete and select the blue chanel. CMD Click the chanel thumbnail and then go to select>inverse of shift+cmd+I. This selects the dark areas of the blue channel.

2 Lets head back over the the layers palette and make a new layer over the original layer. Fill this selection with black

3 Make the original image layer invisible and add a gradient layer under the black highlight and go wild – add gradients, colors or any effects. The black highlight really pops on a pink background. Then add some text and you can call yourself a graphic designer! 🙂

Since the black hilight is transparent its really easy to change the background color to create a different effect.

Download the PSD (ZIP) file here.

What do you think?

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Tutorial written by  Niki Brown – author of The Design O’Blog and Daily Design Bits.  Follow Niki (@nikibrown) on twitter!