Since the update to SR17 (6.17.19189.16411, 8/07/2019), I am now seeing thicker printed lines on some objects, as shown below.
Before the update:
After the update:
The thicker lines appear on Technical Details of Layout pages. I have not changed the Options settings.
The line weight problem occurs with RhinoPDF and PDFCreator, so it is probably an issue within Rhino.
I have attached the Print Width setting for Default, which is 0.0 mm.
The thicker lines appear to be shown for surfaces and polysurfaces. The lines for curves appear to be OK.
The page top margin is not being correctly set in the generated PDF file since the Rhino update.
The left and right margins have also been reduced, but not as significantly as the top margin.
I am now using Version 6 SR17 (6.17.19218.13231, 6/08/2019). It appears that the margins have been improved. Although they are not the same as in earlier release candidates, they are acceptable. However, the thicker lines are still appearing.