Posted by dellus on Jan 02, 2019; 6:28pm
URL: https://forum.librecad.org/Printing-lines-are-invisibly-thin-tp5716811p5716817.html

There is no selective filter option. More advanced commercial cad programs do have this, I know. Maybe in a couple of years...
If you have already changed the width of some lines, you can select those with the mouse, then do a "Invert Selection" and use "Attributes" to convert only the rest.
You can't set the default line width for the entire application. But you can set up and save an empty drawing with your settings and use this as a template for future drawings.
You can even set this for automatic start up for a new drawing in  Application Preferences - Path - Template.