The out of box settings for line weight are in 1/100ths of a mm. Controlled from the Sheet Setup Dialog.   A standard common mechanical pencil will have a lead of 0.7 mm which translates to a line weight of 70. In typical CAD standards 18 is considered to be a fine line using those settings.   A line weight of 1 will be very narrow, but isn't the finest line available. A line weight of 0 will draw as 1 pixel on the device you are using. On a printer that prints at 1200 DPI this will almost d