Cross apps pdf problem

Question

I often have to open pdf's in illustrator and when saving back and opening in acrobat i sometimes get very thin white lines and boxes.
I've been told this is just the view in acrobat and this will not print.....but i had a instance where they did.
anyone had this problem and found a solutiion?

Answer 1

@martin: Do you really need to open PDFs in Illustrator? Although it's possible, Adobe advises against round-tripping PDF files through AI. The ability to open PDFs in AI is intended so you can move a PDF document into an AI workflow (e.g. adding a logo to some artwork), but the PDF files that AI saves are created using different code - Acrobat isn't involved - and as you've found it can often introduce strange effects.
@Alec : If you're seeing 1-pixel-wide white lines on screen at certain zoom scales (especially in conjunction with bitmap images) which aren't part of the original document, it's likely to be the result of ID slicing the page elements up into blocks for efficiency. Although they will line up exactly (and so print out OK), some of the display options in Acrobat (enhance thin lines etc) can reveal them if the zoomed scale of the screen image means the division between slices appears at a fraction of a pixel. Provided the files print OK there's nothing to worry about, but if your document is destined for screen display and it's bothering you, there's a Preflight fixup in Acrobat Pro to "detect and merge image fragments" which usually helps.