You should perform a plotter calibration only if your drawings must be exactly to scale and your plotter or printer produces inaccurate plots. You can adjust plotter calibration to correct scaling discrepancies, and you can add custom paper sizes for nonsystem plotters. If your plotter meets the manufacturer's specifications for accuracy of scale, a 10 inch line in a drawing plotted at a scale of 1:1 should be exactly 10 inches long on paper. If you need to correct scaling discrepancies, you can adjust the plotter calibration.

If your plotter provides a calibration utility, use that utility instead of the autocad calibration utility so the calibration is available for all applications using the plotter. To calibrate a plotter, you must specify the dimensions of a test rectangle, print the test rectangle, measure actual dimensions, and enter the actual measurements in the calibrate plotter wizard. When you complete the calibrate plotter wizard, autocad creates a plot model parameter pmp file to store the results of the calibration for each plot device. Autocad automatically attaches the resulting pmp file to the plotter configuration pc3 file that you used to perform the calibration test.

Calibrating a plotter creates a plotter model parameter pmp file that contains calibration information. If the pmp file is not already attached to the plotter configuration file pc3 you are editing, you must create that association so you can use the pmp file. If the plotter was calibrated from within the add a plotter wizard, the pmp file is already attached. You can use the calibration and user defined paper sizes option to add pmp files to and detach pmp files from the pc3 file. If you have more than one pc3 file for a device, you can attach the same pmp file to them using the plotter configuration editor.

Because pmp files are plotter specific, it's appropriate to attach only one pmp file to a pc3 file. Note you should perform a plotter calibration only if your drawings must be exactly to scale and your plotter or printer produces inaccurate plots. Plotter calibration causes autocad to rescale all plots sent to your plotter to correct errors in its hardware scaling. It is recommended that you use any calibration setting provided by your plotter instead of the autocad setting. Custom paper sizes for a nonsystem plotter, you can choose the add option to create a custom paper size or change the printable area of a standard or nonstandard paper size.

Using the custom paper size wizard, you can create a new paper size or select from a list of available paper sizes from a pmp file. For a windows system printer, use the custom properties option to adjust paper settings. You can modify standard paper sizes to adjust the printable area to match a printer's capabilities. In the plotter configuration editor, you cannot create custom paper sizes for windows system printers, but you can correct errors in the printable area of standard paper sizes. you can also calibrate a plotter by running the plotter configuration editor on an existing pc3 file for the device you want to calibrate. On the calibrate plotter rectangle size page, in the units list, select the measurement units. On the calibrate plotter measured plot page, in the measured length and measured width boxes, enter the actual dimensions of the plotted test rectangle.

Autocad compares the actual plotted measurements to the size you specified in the preceding screen and computes the correction needed to accurately calibrate the plotter. Choose finish to return to the add a plotter wizard or plotter configuration editor. to attach a pmp file to a pc3 file after you create a pmp file, that file is attached to the pc3 file from which you started the calibrate plotter wizard.