Making a "Pop-Out"
A pop-out is a commonly used technique in magazine and newspaper publishing where certain details of the imagea head, an arm, a legbreak out of the image's bounding rectangle. There are several ways (aren't there always?) to accomplish this. But if the image will be placed in a page layout program, the technique that offers the most design flexibility is to sandwich two versions of the image together in InDesign: one version is uncropped, the other has a layer mask defining which parts of the image are masked and which parts protrude outside of the bounding rectangle.
Figure 4.50. Two versions of the same streetcar: full frame (example A) and the other masked front (example B).