Each object you create has an AutoCAD LT color that is assigned either by layer or specifically to the object. Although these colors can correspond to plotted colors, they more frequently are used to distinguish different layers on the screen. When you plot, you can use colors to assign line widths or weights, for example, as specified by your company's standards. How you assign pens depends on whether you use a pen plotter or a raster printer.
Even if you use a black-and-white plotter, you can use layer colors to control line width. When you plot, you assign each color to a certain pen. Your plotter then uses the pen (or pen width) associated with the layer color.
For most pen plotters, the physical width of the pen determines the plotted line weight; however, some plotters can simulate a specified pen width by using multiple pen strokes. If you plot filled solids or wide polylines, be sure to configure the pen width to match the physical width of the pen.
Many plotter pens mark pen width in millimeters. Be sure that the unit type of your pen width entries (inches or millimeters) matches the unit type specified by the pen manufacturer. If you are working in inches but your pen tip measurements are in millimeters, you can select Millimeters in the Plot Configuration dialog box, make your pen assignments, and then switch back to inches.
For raster printers, such as laser, inkjet, or electrostatic printers, which do not have physical pens, you can plot various line widths by assigning a pen width to a color. You may want to configure these widths to match the most common pen sizes: 0.18 mm, 0.25 mm, 0.35 mm, 0.50 mm, and 0.70 mm. If you can specify pen widths on the hardware, be sure to change the hardware settings to read the software pen width values.
For both pen plotters and raster printers, you can associate the same line width with several layers by assigning more than one color to a single pen. For example, suppose you have set up a blue and a red layer. If pen 1 has a width of 0.25 mm (whether the width is physical or assigned), you can plot 0.25 mm lines for all objects on the blue and red layers by assigning both the blue and red colors to pen 1. If you are using a color plotter, this assignment also causes those colors to be plotted in the same color.
Some plotters support hardware linetypes, which are supplied by your plotter rather than by AutoCAD LT. You can display these linetypes by choosing Feature Legend in the Pen Assignments dialog box. Although they are usually faster than software linetypes, these plotter-based linetypes are used less frequently than the AutoCAD LT linetype styles. They may be useful if you want to plot a different linetype without changing the linetype style in the drawing. If you change linetypes in the Plot Configuration dialog box, avoid unexpected results by making sure that the affected objects use a CONTINUOUS linetype.
For some pen plotters, you can adjust pen speed on a pen-by-pen basis. This feature is useful, for example, for slowing down pens that are skipping. Each pen manufacturer recommends a pen speed. For best results, use those values.