You can set the scale for your drawing as a ratio of the working units to the printer units. Default printer units are specified in the printer driver configuration file’s Driver Resolution Units property. You can change this by selecting Settings > Units and then choosing new units from the subsequent menu. The options are: inches, feet, mm, cm, dm, m.

Even if your printer is not set up with exactly the same units as your drawing, you can specify the scale of your printed output as a ratio of working units (mu:su) to printer units. Consider, for example, your design file having Master Units of Feet (MU), while your printer’s units are Inches.

To create a 15 feet to the inch scale output would require no changes to the printer's units. You would enter 15 in the Scale field to make the printed output scale 15 ft per in.

To create a 1:20 scale output, you could first change the printer's units to feet, to match the design file's master units. You would then enter 20 in the Scale field. That is, the printed output would be 20 feet per foot or 1:20.

For more complicated scale values, you can use the Scale Assistant to help you set the correct scale. The Scale Assistant enables you set the scale as a ratio of Paper to Design, or Design to Paper.