Did you know that you can show your PDF drawing with vector lines? (simply said: lines that have constant (thin) line weights no matter how much you zoom in).
You will need to open your drawing with Adobe Acrobat Reader. Thin lines feature in Adobe Reader works shows content the same way such as Thin Lines command in Revit, for example.
Of course, this works only for PDF drawings produced with vector (CAD) software such as Revit and AutoCAD.
To achieve this in Adobe Acrobat Reader you need to press keyboard shortcut Ctrl+5 or go to View > Show/Hide > Rulers & Grids > Line Weights
To illustrate more, compare the two images below. They are from the same PDF document and show before and after switching Adobe Acrobat Reader Line Weights option off: