How to Create a Background Layer for Your Photoshop File (and an Action for Your Sanity)
There are two purposes to today's tutorial. First, to reveal the Photoshop secret handshake for creating a new background layer. Second, to show you how to create an action so that you don't have to perform the entire handshake every time you want a new background for your file.
First, a point of order. Deke prefers (possibly insists, but he's not answering my call at the moment so I get to do what I want) that one refer to the background layer as simply "a background," because it's not really a free-floating layer. It can't move up the layer stack, it can't be repositioned in the image, it's always the same size as the canvas, and it can't be transparent. For these reasons, I get what Deke is saying. But I'm afraid if I just call it "background" you're gonna envision green grass and blue skies.
The background layer is most useful for seeing your image against a white, well, background. I'd be willing to guess that most printing of images is done on white paper, and adding the background layer allows you to assess how your image will look when you print. For instance, in the image below, it would be hard to gauge that drop shadow on the gray picture frame element if you were seeing it against a transparent background. Especially since Photoshop indicates transparency with a gray and white checkerboard pattern. But with this background layer in place, you can see (and adjust) that drop shadow accordingly.
Thing is, creating a Background from an existing layer is a little bit obtuse, in that way that Photoshop can be. Sure, it's only three steps, but I have an entire blog post to write. So, as a bonus to my instructions, I'm going to show you how to record an action that will give you a new background [layer] with a mere keystroke without remembering where that tricky command is hidden. Read to see how it works:
1) Create a new action.
Like I said, this process is a minor annoyance, so I'm going to capture it in an action to make it less tedious. Open the Actions panel (Window > Actions, if it's not already open) and click the page icon at the bottom of the panel to create a new action. In the dialog box, name it "Make New Background" (or whatever you like). At this point, you can also assign this action to run whenever you hit a particular function key. In my case, I've set it to F1 and added the Command key to modify (because I already have another action assigned to F1 by itself). When you click Record, Photoshop starts tracking your every move and adding those actions to your Action.
2) Make a new layer.
You need create a new layer that will eventually become the background. Now normally, you probably pay attention to where in the stack your new layer is added and (of course, because you are diligent) you name your layer as you create it. But when this layer becomes the Background, its going to automatically go to the bottom and be renamed "Background." So the simplest way to create that layer is just to click the page icon at the bottom of the Layers panel and don't worry about the rest.
3) Set your foreground and background colors to their default settings.
Nine times out of ten, you're going to want your background to be white, so that's the logical color to record your action with. If you click the D key at this point, it will set the colors to their defaults, with white as the background color. The action will record this setting, and ten times out of ten it will give you a white background. (You can always change the 10th time to your liking by hand once the action has played.)
4) Change the new layer to a background
This is where the secret handshake resides. Your new layer is already selected (presuming you haven't done anything tricky), so from the Layers menu, choose New > Background from Layer. (Hmm. Maybe Deke is right; it's just called Background here.) Voila, your new transparent unnamed layer goes to the bottom of the stack, fills with white, and takes on the name (and properties) of Background.
5) Enjoy your new background.
Note how much easier it is to assess the drop shadow (and possibly tone it down) on the side with the white background instead of the transparency checkerboard. I mean the transparency isn't going to print, and so you might as well see what you're gonna get.
6) Stop recording.
Sometimes when you're recording an action, it's easy to forget to stop. You blithely keep working and end up with a comical list of everything you've been doing for the last five minutes. (No, this has never happened to me, except always.) If you want to tweak the steps of your action without having to re-record, you can drag unwanted steps to the trashcan at the bottom of the Actions panel.
Fortunately, this time I remembered to stop recording (as far as you know.)
From this point on, you can simply press Shift-F1 (or whatever Function Key + modifier sequence you designated in step 1), and Photoshop will automatically create that handy white background for you.
Like shortcuts, actions require a little investment up front. But for sequences of things you do often, it's a real sanity- (and wrist-) saver. I've got actions like "Make from Clipboard" and "Reduce to 75%" that I use over and over, especially when making my obsessively intricate screen shots for posts like this one. What about you?