Pen Weights

Well drafted drawings contain lines of varying thickness. How do I control line weights in an AutoCAD drawing to be plotted on colour inkjet printers?

AutoCAD plots by colour. Construct your drawing using lines arcs, circles etc. with different shades of the one colour. You might for example want to use red for existing trees in a landscape plan. Draw the circle representing the trunk in colour 240 (a shade of red), the canopy outside diameter in colour 20 (a different shade of red) and cross lines in the canopy in colour 10 (another shade of red). 

Now choose File>Print and click on pen settings. The default pen thickness' (0.025) are too wide for modern inkjet printers which are capable of 720 by 720 resolution. Firstly, set all pens for all colours to 0.018. Now increase the thickness of the pens to give appropriate emphasis. 

E.g. you might set pen 1 (red) at 0.018 and colour 10 (a slightly different shade of red) 0.036 and colour 20 (another red shade) at 0.072 and colour 240 at 0.108 to give 4 different thickness' of red. Other colours can be set appropriately. Note that you can create an a4 size drawing with line weights looking a little on the thin size and then enlarge to A3 size on a colour photocopier for very good results.

Save the setting in a .PCP file.