Hi Graham,
Welcome to the forum.
Can you please post the question in to the AutoCAD Forum instead, as this is an AutoCAD question?
Regarding this issue in AutoCAD 2018, this is likely the result of the HIDEPRECISION system variable being set to 0 and the visual style of the model set to Hidden.
Can you please try the following on your side?
- On the command line in AutoCAD, type HIDEPRECISION.
- Change the value to 1.
- The visual style of the model should be kept to "Wireframe."
- If the issue persists, please use MVIEW (Command), change the "Shadeplot" to "As displayed", then select the viewports and print.
Please let us know how it goes.
