Also, thin lines with high contrast (ie black on white) are always a difficult proposition in DV. If you work in a better quality codec, you'll yield better results, but you're fighting a bit of an uphill battle with any drawings with lines less than about 3 pixels wide.
You could try less detail, less contrast (dark grey on off white) and thicker lines, but that sounds like an awful lot of work on 1500 CAD drawings, really..
I have never suggested this before, but, perhaps this would be better done in Keynote or PowerPoint and run off a computer? Where and how will you be presenting this?