I have started using InDesign recently with one minor problem. It is all fine until I export using PDF/X-1a:2001 (as I have been erecommened to do as it converts to CMYK etc). When I then view the PDF it shows slight frame edges around objects, however i have no stroke etc selected. When i export using any other PDF preset or as a JPG these do not appear. Having googled the issue it appears that they are just transparency lines which will not print, however i'm a bit hesitant to send jobs to clients/print with these appearing.
All advice would be appreciated.
I'm using CS5 on OsX
Check with your printer and see if your printer requires transparency to be flattened (the PDF/X-1a option). As long as you're flattening, you may run into these artifacts. You're correct: These artifacts don't print on high resolution devices. If you're sending a file for review, you could export using a PDF preset that doesn't flatten (e.g., High Quality Print).
As Steve says, but…I would go back to whomever recommended that and ask why.
The 2001 in that standard is the year. X/1-a is very old standard used in archaic workflows and it's really not unheard of for publications to ignore their file specs even after updating equipment and workflows.