When you place (not import) a PDF in a ArtPro file, the resolution shown is very low even if the PDF is exported with a preview higher than 72 dpi. How to view the placed PDF in a higher resolution?
To view the placed PDF in a higher resolution:
Place the PDF file (Picture > Place), you will see a checkered low resolution preview of the PDF file.
Right-click on the placed PDF file and click Calculate PDF Preview.
If you close your ArtPro file after increasing the preview resolution and open it again, you will see that the the preview has returned to it's original viewing state. You will have to click Calculate PDF Preview again to view it again in a higher resolution.
However, if you choose the Add Preview to PDF option instead of Calculate PDF Preview, the preview is added to the PDF and will show up in the calculated preview resolution the next time you open the ArtPro document.
This will increase the file size of the PDF document