A plotter is an automated output device used to print vector graphics, very much like a printer. You can choose between drum plotters and flatbed plotters. Each has its advantages and disadvantages, making it important to understand the differences before purchasing.
As opposed to normal printers, plotters create high-quality, large-scale, line drawings. A pen is affixed to a mechanical arm and held over paper to create lines. Because plotters use lines to create images, they are unable to print solid areas of colour. They create the illusion of solid areas of colour by drawing a series of very close coloured lines. Plotters are used when computer memory is scarce and processor power is limited.
The drum plotter has a pen affixed to a mechanical arm that moves on a single axis track--for example, it may move from left to right. In order to add a second dimension to the image, the paper is affixed to a cylindrical drum that rotates underneath the pen. The length of a drum plotter's image is infinite, but the width of the image can be no bigger than the width of the drum. Drum plotters tend to be smaller because of this.
A flatbed plotter's mechanical arm can move left to right and forward to backward over a fixed sheet of stationary paper. Because the paper is fixed, it can print an image size equal to or smaller than the size of the flatbed. Flatbed plotters tend to be larger because of this.
Hewlett Packard, Canon and Epson are all popular brands of plotter manufacturers. The price of a plotter, whether it is a drum or flatbed, will depend on its size and the number of colours it can print. A new plotter can run from £455 to £5,850. Used plotters are also available, and plotters that are 20 to 35 years old typically still work very well.