I created a document in InDesign CS5.5 that had a background image and, on top of that, a small circle to act as a cutter guide so that the printer knew where to drill a hole for binding. I set the circle to 'overprint' in the attributes pane, and then exported the layout under the PDF/X-1a:2001 setting in Acrobat. Later, the printer said that the circle was in fact knocking out from the background image, even though separations printed from my laser showed the circle on its own separation and no hole knocked out of the image. Any idea what I've done wrong?
Many thanks if anyone can put me right - Andi