hsrai,
Thanks for your reply.
I have tried printing to PDF with various scale factors ranging from 1:1 to 1:25. The nearer I get to 1:25 the more of the drawing appears in the print but the smaller it gets (even looking at it with the PDF viewer set to 400% it's tiny though it is complete!).
But as I said in my second post above - the files which give this printing problem are not created in LibreCAD, but exported as DXF version 2010 from another CAD program. I have also discovered that DXF files are plain ASCII which can be edited in a text editor (I didn't know that
!). I have also downloaded the DXF 2010 specification. So with a bit of study and testing I might be able to figure out what's going on here.
Nevertheless any tips to help out, or warnings, would be very welcome!