Thank you all for your suggestions. I, too, see a grid in some readers (e.g., Evince on Linux) but it's not a grid of sharp white lines; it's just a noticeable artifact of tiling the background (sand.jpg from the LibreOffice gallery). Apparently its edges don't join smoothly; it wasn't (virtually) printed on a torus and then sliced. I think this is a separate problem from my very crisp 100% white horizontal-only lines.
I was kind of hoping someone would declare this an official LibreOffice bug and fix it, or come up with a good workaround. I don't want to have to redo the whole project in Adobe Illustrator or something. -- View this message in context: http://nabble.documentfoundation.org/Unwanted-horizontal-white-hairline-rules-in-PDF-in-Mac-Preview-tp3552492p3555093.html Sent from the Users mailing list archive at Nabble.com. -- For unsubscribe instructions e-mail to: users+h...@global.libreoffice.org Problems? http://www.libreoffice.org/get-help/mailing-lists/how-to-unsubscribe/ Posting guidelines + more: http://wiki.documentfoundation.org/Netiquette List archive: http://listarchives.libreoffice.org/global/users/ All messages sent to this list will be publicly archived and cannot be deleted