Layer masks using Channels

PhotoShop: In this example I will show you how you can make a background of an image transparent, for instance if you want to make a path around a product but still use it’s shadow to overlay underlying images. This is also known as an “Alpha channel”.

This first image is the image I want to use, and as you can see it has a white background with an overlying shadow of the product.

Start by selecting a path around the product using your masking tool of choice, preferably the pen tool. But also note that some supplied product images have already an embedded path, you can find those in the Paths palette in most cases.

With the path selected, create a new layer by pressing CTRL+J, this will create a new layer from your selection.

Now create a “Solid Color” adjustment layer and select black for the base color. Your layers palette should now look something like this:

Select the backbround layer and press CTRL+A (select all) and then copy it (CTRL+C). You now have the original image in the clipboard. Select the black adjustment layer again.
Now go to the Channels palette which should be right next to the layers palette and you can see in the bottom of the palette there is a hidden channel called “Color Fill 1 Mask”, select it and make it visible by pressing the “eye” icon.
With the channel selected, paste your clipboard by pressing CTRL+V. Right after pasting, press CTRL+I to invert the image you pasted into the channel. Your channels palette should now look something like this:

Still in the Channels palette, select the eye icon next to the “Color Fill 1 Mask” layer to hide it.
Now select the Layers palette and you will see that an image mask has been created for the black adjustment layer. You can now just delete the background layer as you will not need it anymore. Now your layer palette should look something like this:

And your finished image should look something like this:

As you can see the shadow is transparent, so to finish it up, link the two layers together or merge them (a good rule is to have these layers seperate and select a Multiply blending mode for the shadow layer). You can now drag these layers to another open image and see the effect of your overlaying transparent shadow.

Color space copy

 

Photoshop: When copying from illustrator or freehand and pasting into photoshop and your color comes out differently than you intended, try to change the color space of Illustrator into the colorspace you have currently set in Photoshop. Matching colorspace (RGB to RGB or CMYK to CMYK) copying will produce better results for your designs in photoshop.