Posted by chlor on Apr 05, 2019; 11:39pm
URL: https://forum.librecad.org/Start-new-drawing-Paper-size-units-scale-tp5717205p5717209.html

Thanks, exactly what I want.

I got the idea but don't have that drop down scaling box on your screen shot.
I found the equivalent in the menu:
Options -> Current Drawing Preferences -> Dimensions -> General Scale

So if I want to draw a 2000 by 1100 micro meter square I just change the text "mm" to "µm" and the text scale from "1:10" to "100:1" and the rest is the same - still A4. In the opposite way around if I want to draw an inter galactic football field measured in light year.