The dotted line at Print Preview have Display problem
In SketchUp, go to Window>Preferences>OpenGL. Turn off Hardware Acceleration. Click OK. Reopen LayOut and try Print Preview again. Does that fix the problem?
This is an issue with the Print Preview dialog and how it displays lines with patterns. Unfortunately, that’s a system dialog and we haven’t figured out a way to fix it yet.
Thinks，but this issue is in Layout，no in SketchUp.
Thinks for you reply.
I understood that when I wrote my post. OpenGL settings made in SketchUp affect the way the GPU/CPU handle output from LayOut, too.
It’s not a major problem if you want a clean print preview, then using the adobe photoshop pen tool (remove the background)