Line weight is shown right in drawing mode at scale 1:1. At a drawing intended for 1:100 they seem very thin, but they are in fact the same, for example 0.5 mm in real life on a 10 m long wall. Print Preview shows them as 0.5 mm on an A4 sheet at 1:100.
Linetype is always rendered with the same dash spaces on paper or pdf, regardless of scale.
You can print out this sheet, so you will know how they will look on paper:
linetypes.pdfThese are known limitations in LibreCAD, which also have been discussed before. There are many things to be improved, the problem is there is no one to do it.
Maybe when LibreCAD 3 appears it will address these deficiencies.