Posted by dellus on Dec 04, 2022; 6:43pm
URL: https://forum.librecad.org/Incomplete-Drawing-Printout-Solved-tp5722240p5722242.html

Depending on your printer, or printer software/driver, entities with linewidth 0.00mm, or Default, which is the same, may be printed very faint or not at all.
The same applies when printing/exporting to pdf, depending on the pdf-viewer app. Some such apps allow a choice how to handle hair lines.
Print Preview always shows lines 0.00mm wide.

Linewidth of entities is defined either individually by pen properties when drawing them, or as an attribute of the layer they reside on (pen property "By Layer").

See the manual https://librecad.readthedocs.io/