OmniGraffle print line effects (plastic) renders to low DPI

I’ve exported my image to PDF. and noticed that the plastic effect on my line and shape style is rendered, not vectors. And the DPI of the objects is low (less than 100 DPI).

How to change the default DPI of OG element with effects?

Also all of my drop shadows are 12 PPI. Yikes!
Any ideas how to fix?