I have a map with several layers with different thickness. When I export into PDF there is no difference in thickness. Practically lines 0.25mm and 0.5mm are exported all as 0.5mm. When I export this map into JPG the thickness it is OK, it can be visible even without zooming in the map.
The fast solution is, I can export into .svg and create the PDF by using Inkscape.
I need to export directly from ArcMap 10.5 because I want to automate some stuff.
This screenshot is of two images exported from the same layout.