One on the most fundamental part of drawings that will help strengthen the quality of each drawing is line weight (Some people prefer to use line width).  Line weights convey depth and indicate various functions of each line in drawings. It is also portrays the appealing of drawings if line weights are assigned to drawings properly. I have been trying to explore the effective method of utilizing the line widths in architectural drawing (AD). I recently have come to the final conclusion of categorizing  line widths for both computational and manual methods of drawings in to three sizes.

-Thick line depicts cut edges of solid components:

Setting for computational method: 0.35 mm in metric, 0.014 in. in U.S measuring system. 1 pt. in graphic application

-Medium line uses for cut glass plane.

Setting: 0.18 mm., 0.007 in. and 0.5 pt.

-Thin line depicts visible, concealed, and projected edges

Setting: 0.09 mm., 0.003 in. and 0.25 pt.