How to create clipping masks in InDesign

Creating clipping masks in Creative Suite has a different approach for each of its programs, despite being a 'suite'. Here I'll explain how to mask an image or object in InDesign.

A clipping mask is simply the masking, or selective hiding, of parts of an image or object against a given shape. The shape can be rectangular, circular, or an arbitrary path drawn with the pen tool. It's the preferred method of cropping as the designer can non-destructively crop an image, for example in a magazine layout, then move the mask around the image in order to find a better crop.

If you're used to creating clipping masks in Illustrator or Photoshop you might find doing the same in InDesign a bit baffling at first - I know I did! Illustrator has probably the most logical way of dealing with masks: Path on top, image below, select both objects, highlight the path in the layers palette and hit F7 - a new group is created with the clipping mask on top, easy! Photoshop works the opposite way, obviously: Image above, path below, in the layers palette Alt-click on the dividing line between the two layers. Or use the new 'Mask' palette in more recent versions of Photoshop, which has a nifty opacity and feather feature, which is quite nice for softening masks when used in a montage.

InDesign requires you to do a third process. One must 'Paste Into' the mask!

Images brought into InDesign from Finder/Explorer/Bridge will automatically have a clipping mask attached. Try it: Selecting an image with the direct arrow pointer (black arrow) will select the image and give it a blue bounding box with handles:



Now deselect and reselect with the indirect arrow pointer (white arrow) - notice the bounding box is now brown with handles?



The blue represents the clipping mask which can be resized, cropping or masking the image:



The brown is the actual limits of the image, which can extend invisibly beyond the blue mask. One can use the brown handles to resize the image directly (keeping a finger on the Shift key to keep proportions, of course).




Scenario: You've just created a shape with a gradient, or some outlined type which you want to mask against another shape - how do you do that?

Well, simply create your object:



Then create your new mask shape:



Select the object you want want masked and Edit>Cut or Cmd+X:



Then select your mask and hit Edit>Paste Into or Alt+Cmd+V:



Voila! Your fancy gradient is now inside your mask!