Lines in PDF images

[Rick_Meikle@adobeforums.com]

I'm making a "press quality" PDF file from Illustrator CS2 (using "Save as..." command). The file contains CMYK images from Photoshop CS2 in either EPS or native (.psd) format--I've tried it both ways--and those images are being sliced into horizontal sections (rectangles). I might be able to live with that, but the background is visible through the hairline gaps separating the horizontal sections. These lines are visible in Mail (as it displays the attached PDF file) and are visible at the vendor on screen AND on printed output. (Stuffing the PDF file before emailing does not make any difference.) BUT the lines are simply not there (the images are whole) when the PDF file is opened by me in Illustrator or Acrobat. I can put the same job through Illustrator 8 and Distiller 4 (tried-and-true OS 9 workflow) without a hitch. Does anyone know what is causing the images to be chopped into rectangles and how to keep that from happening?

[Rick_Meikle@adobeforums.com]

I'm following up my own posting. There are a couple of lengthy topics in the Illustrator forum about this, which is also referred to as "stitching". It appears to be a bug in AI10 (or perhaps an unfortunate decision by the Illustrator team). It affects placed EPS and .psd files. (The former more than the latter.) CMYK mode may also be implicated. Workarounds suggested:

-- Embed placed image, then Undo after generating PDF file.
-- Do not use "Save as..." to make PDF. (Save as EPS, then use Distiller.)
-- Use TIFF instead of EPS or .psd.
-- Turn off "anti-alias artwork" in Preferences (hunch: may still split image into sections, but lines not visible).
-- Set Printer Resolution much higher (in Print dialog box, but this is not available through Save As...).

I'll try these--at least until I find one that works--and report back.

[Glenn McDowall]

"Photoshop pdf" seems to have a higher pixel threshold than eps or psd, downside is you have to workaround any clipping path.

Duotone EPS is the worst offender for me.

Another tip is to keep the images in the same folder as the ai file, this stops the links becoming embedded art (and sliced) upon opening on a different machine.

I'm really hoping CS3 will resolve this one.

[Rick_Meikle@adobeforums.com]

Amen, Glenn, regarding CS3. (However, in my case, the AI file and the images were in the same folder all along...and the stitching still happened.)

This reminds me of when color management came along and Adobe tried to force everyone into an RGB workflow even though the printing world spoke CMYK and color management was a moving target even within Adobe apps. (Even now there are rough edges that are way overdue for smoothing. When will Illustrator learn to speak LAB, for example?)

The current evolutionary process involves a PDF workflow (among other things). It may be that all Adobe apps should generate PDF files all the same way (or ways). I wouldn't mind a "Make PDF" command common to all apps, probably adjacent to Print in the file menu. It would bring up full controls. (There would also be "simplified" settings available. And the settings could be intuitively edited right in that dialog nest, with full pop-up help.) Yes, and pigs will fly, too.

For the time being, embedding the placed EPS or .psd file solves the stitching problem. That was the first thing I tried. I expect at least a couple of the other workarounds would work fine, too.

[Glenn McDowall]

Hi Rick

what you describe to make common pdfs, is sort of built in to CS2/Acrobat7 in that they share "Distiller Settings files". Although each app seems to have a few extra options not shared by the others. It is also obvious that Illustrator is the poor relation of the family since ID and Distiller don't slice up placed EPS.

Embedding the placed EPS seems to make matters worse for me.

I've taken to quickly checking that Illustratrator PDFs have no sliced images by using PitStops wire frame mode. Wherever possible I replace a placed eps with a psd, if its a big image I'll save it as photoshop pdf.

What is really awkward for me in pre-press is that these lines when viewed in Acrobat look just the same as the anti-aliased stitching lines (created by properly flattening) which don't print.

[Rick_Meikle@adobeforums.com]

Yeah, it's the "sort of" aspect that bothers me. Sharing Distiller settings files is not the same as having the same menu/dialog/process in all Adobe apps. Instead, you're given three or four different ways to get the job done, but there are subtle or undocumented differences in each route--and between apps, as well--that can burn your time and blow a deadline. As usual, the only solution is to learn the pros and cons of each approach in each app the hard way. Of course, that's when Adobe upgrades the software and you have to start over.

So you still get slicing even after you embed the EPS image? The only drawback I could see (besides remembering to do it) is the PDF file is much bigger. Something like 8x bigger with the job I was working on. But the larger size was more consistent with what I would have expected from AI8 and Distiller 4.

I'll keep the Photoshop PDF solution in mind, but the size of some of my projects (large posters & tradeshow graphics) pretty much ensures I've crossed the pixel threshhold regardless of file format.

I also gather that I confused the anti-aliased stitching lines with the "sliced image" lines we're discussing. I'll skip the long story involving sticking with older apps and a known/reliable workflow. It's finally time for me to get on with leaving the past behind...