Here. I made you a quick sample thing with various line weights (scales). I used the same size paper you used in the project you shared. Print it and compare the results.
Line Weight Test A3.pdf (7.9 KB)
Thank you. That is very helpful indeed
ISO drawing standards call for line weights in a drawing to be based on 2x differences, with the thinnest line being 0.13 mm (about 0.3 pt) that gives a sequence of 0.13-0.25-0.5-1mm. This ensures that the eye and an eventual microfilm camera can discern between the weights. Perhaps the sequence 0.18-0.35-0.7mm is even more common. 0.18 mm would be approximately 0.5 pt. Usually it is recommended that no more than three weights are used.