Once you've got a template, you define which layers of the template will be replaced by data. A Photoshop layer can contain any of three kinds of variables:
Visibility. Is the layer visible or not? You control that with this simple on/off variable.
Pixel replacement. Replace a layer with an image so that each instance can have a different picture.
Text replacement. Replace a layer with text.
In my example, I have four variables:
Product. This is the name of the product, and I define it as a text-replacement variable.
Price. This is the sale price of the product, which I'll define as a text-replacement variable.
Image. This is the image of the product, to be defined as a pixel-replacement variable.
Organic. This indicates that the product was grown organically, and I define it as a visibility variable, because the only thing that changes is whether this type layer is displayed or not.
To define a variable:
Choose Image > Variables > Define.
From the Layer pop-up menu, select a layer that you want to assign to a variable. My template contains a layer for each variable I want to use (Figure 20.2).
Under Variable Type, enable the checkbox for the variable you want to use. Enter a new variable name or select an existing variable name of the same type by clicking the pop-up menu to the right of the name.
If Pixel Replacement is available and you enable it, you can specify how images of different sizes should fit on the layer:
The Method pop-up menu specifies which resizing method to use; select one and read the help text at the bottom of the dialog box to see if it's the right choice. I'm using As Is because all my images are already sized properly.
The Alignment proxy anchors a resized image to the center or an edge; click a point to set it. The Alignment proxy doesn't apply in my case because I selected the As Is method.
Clip to Bounding Box, when enabled, doesn't display areas of an image that are scaled beyond the edge of the image's original bounding box. Disable it to always display all of the image.
5. When you're done defining one variable, you can do one of the following:
To assign a variable to another layer, click the Prev or Next button.
To continue on and work with data sets, choose Data Sets from the pop-up menu at the top of the screen.