I created a picture in Photoshop with a transparent background. I saved it as a PDF to hold the transparency and then placed it into an InDesign file that has a blue background. On screen it looks fine, but when I print it there is a darker blue box around the picture. Obviously I am looking for the plain blue to show through behind the picture and not the box surrounding it. How do I remove that? Thanks for the help.
Saving as PDF preserves any live vectors or type. I suspect what you were experiencing was YDB (Yucky Discolored Box) which is printer issue, not a problem with the file format. See InDesignSecrets » Blog Archive » Eliminating YDB (Yucky Discolored Box) Syndrome
Since it depends on how the equipment handles the processing of continuous tone and linework theres no single answer to that. Newer equipment seems to be getting away from the "dual-level" processing (I haven't seen this problem on output in a few years, but that doesn't mean it isn't still out there in some shops).
If the printer can handle the live transparency, that's a good sign, and you should send a PDF that is not flattened.
Our printers are kind of old.
Are we talking about physical printing devices you use to make output, or people you send files to to have them printed?
If you get the YDB problem on your own printers, then the article outlines the only way I know to work around it.
Europe, Middle East and Africa