Scale Lineweights for Plotting

Today’s post is about a small but extremely useful checkbox at the bottom of the Plot dialog. (You don’t even have to have the dialog expanded to see it.)

“Scale lineweights” goes into effect when you’re plotting a drawing at something other than 1:1. Maybe you have a 22x34 drawing that you need to plot on 11x17, or a 36x48 drawing that you need to plot on 12x18. Maybe you’re even plotting a blow-up of something.

Without “scale lineweights” checked, the drawing just uses the lineweights in the current CTB or STB file. This can result in a very black and unreadable plot, especially if you’re printing out something very small. But if you check the box, AutoCAD LT uses the plot scale ratio to scale the width of your lineweights appropriately.

To give you an idea of how important this can be, here are 3 plots of the same drawing; one at full size (30x42), one “fit to print” on 11x17 without scaling lineweights, and one “fit to print” on 11x17 with scaling lineweights.

Full Size:

11x17, no scaled lineweights:

11x17, with scaled lineweights:

And if you can’t tell the difference between #1 and #3, remember, that’s the point. But just to really prove it to you, here are links to the DWF files I took those screenshots from.

• Full Size
• 11x17, without scaled lineweights
• 11x17, with scaled lineweights

Comments

[Andy]

Scale lineweights in AutoCAD is still crude. If you study dimensional similitude ( http://en.wikipedia.org/wiki/Similitude_%28model%29 ) in physics, not everything scales equally.

Instead of using scale lineweights to plot at 22x34 drawing onto 11x17, I created a new plot style table that steps lightweights down rather than cutting them in half .. e.g. .7 mm to .5 mm, .5mm to .35 I think this yields better results.

[Andy]

Also, when scaling down to 11x17, often it is printed to a laser printer that doesn't do fine lines as well as a plotter.

Another consideration of course is the overall density of the drawing and the amount of fine lines.

Point is, scale lineweights may not be enough and CAD departments may need to put a little more thought into making 11x17 drawings print out well on their intended printer, especially since they are so handy and increasingly popular.