Expert: InDesign Pro - 11/5/2007

Question
I was just working on an InDesign job that had a colored rectangle (with type
inside) with a Drop Shadow applied to it. This rectangle then overlapped a
full-color photo. When run on press, the black of the shadow would, to
varying degrees, show a noticeable edge in the photo, rather than a feathered
edge. And occasionally, there would also be a soft area of white, or
lightening, in the photo surrounding the outside of the drop shadow.

This drop shadow was created in InDesign, as a percentage of solid black, in
Mulltiply mode.

Can you offer any suggestions as to how to resolve this issue? Would using a
rich black have helped?

Thanks!

Answer
Hi Kevin, thanks for the question.

The problem happened when the transparency in the shadow flattened in the RIP process at your printer's. A rich black wouldn't have helped because a flat black in Multiply mode over a full-colour photo would create basically the same effect.

Without having the document in front of me to trouble-shoot a little more, I can't give you a detailed answer to what might have helped in this specific case, but I can give you a few tips for the future.

Always put type on the top of any objects using transparency (other by using a new layer on top exclusively for text, or by ensuring it's on top on the same layer). And, most importantly, export your files to PDF for your printer using the PDF/X-1a:2001 preset. Then check the resulting file for problems, especially where there's transparency. The PDF/X-1a:2001 preset flattens all transparency and will save it flattening at your printer's without you to verify its look first.

Hope this helps. If you have a follow-up question, I'd be more than happy to help again. Thanks.