Sometimes, when I package a layout, I need to include images in the links folder that are not used in the actual layout. The first time I needed to include a black and white version of a logo I just put it on the Pasteboard and expected it to get packaged with the rest of the images. Lucky I checked! InDesign does not package images that are positioned entirely off the page.
To solve this problem, I temporarily reposition the images so that at least a small portion is inside the trim. After packaging, I just delete the extra pictures so that they are included in the links folder but not the printed piece.
Tip provided by Jeff Witchel, Certified Adobe® Training Provider.