Presumably you're seeing this effect when looking at a PDF.
Which operating system? Any other issues or just this one?
In InDesign go to the Links panel and check what the Effective resolution is for the images. For high quality sheet-fed litho printed on coated stock they should be between 250 and 300ppi.
Thank you for writing, Mr. Cross.
Actually, I'm still in the design face, using InDesign, not in PDF format yet. I am using a PC, with Windows 7 as its operating system.
I tried to get the Link information, but I wasn't able to find Effective resolution information, so how exactly do I obtain it?
Chad Chelius answered that question on on 19 September 2015 on this forum in reply to the same question from you.
I you could please send me the URL, I would greatly appreciate it.