why, when i drag an adobe illustrator document into indesign, do tiny lines, visible only at high magnification with overprint preview turned on, appear on a raster image placed in the illustrator doc? these are easy to miss and will turn up on the printed piece.
The CT or Illustrator file must be an EPS. Save the CT as .psd or tiff. OR Embed the CT in the Illy file and save as .ai instead of EPS. (EPS will flatten the file - thus creating the "stitching" your seeing.
i was given the opposite advice by our printer. i have tried both methods with the same results. the flattening is going to occur at some point in the work flow. i find it hard to believe that no one else has had this problem.
The raster elements are PSDs or Pshop EPSs that are linked into Illustrator. To avoid the problem, the raster elements need to be *either* TIFFs *or* they must be embedded into the Illustrator file. With a PSD file I could see that something is being interpreted as "transparent", but I don't know why the Pshop EPSs react this way.
Does the PDF look this way when opening in Acrobat and turning on Output Preview? This should show us if the problem is the PDF (highly suspected) or InDesign's handling of the PDF. FYI I have Nexus and the first versions of 8 (at least until 8.2) didn't even have the transparency flattening library in the installation?!?!?!, so I consider dealing with the software somewhat like beta testing. Also, my proofing got messed up and I had to go back to a previous version. If you have support, you need to call and ask why the PDF is messed up (if it is the culprit as I suspect), and maybe you can actually get help and not waste a lot of time on testing crap that's not pertinent.
The problem should be a result of improper "Transparency Flattener Settings"
in your "Document Setup" dialogue.
Depending on where the problem shows - it may be the "Document Raster Effects" setting.
The .ai file you are viewing in InDy is a preview only.
What happens if you "Save as" an Illustrator PDF - with proper settings -
then view that with Acrobat (with smoothing off, of course).
i've tried your suggestions and saving the AI file as a pdf seems to be working for the time being. the white lines around areas that have transparency are still visible, but USUALLY do not print. although, in the past, we tried to avoid pdfs made in illustrator as enfocus' pitstop didn't like them. maybe it's different with cs3. a new twist to this mystery: as i've been experimenting with different settings in ID and AI, i've noticed that the location of the "stitching" that will actually print moves around from test to test with no other variables changing. so the problem i am having is not only intermittent, but arbitrary. being extra vigilant is only a workaround in our workflow. maybe someday i'll get to the bottom of this.