Hi Alex, yes when exporting a solid where it will create a hidden-line drawing, it is possible in both MoI v3 and v4 to control the line widths by using the "Line style options" button in the PDF export options dialog:



Then on the "Line style options" dialog, the widths are controlled by this column here:



It appears that your v4 export is using the default values while your v3 export has had them modified.

Did you do the v3 and v4 export from different machines though or from the same machine? If it's on a different machine then you would want to modify your v4 settings to match what you have on v3. If it's on the same machine that might be some kind of bug since the values should be coming from the same section in moi.ini for both v3 and v4.

If you want to sync up 2 moi.ini files, you would copy over the [AI/PDF Export] section from your v3 to your v4.

- Michael