Very often it might be required to create high-quality visuals on paper, which cannot be obtained using a printer. For this purpose, a plotter is used. A plotter is an output device that is used to create presentation visuals, charts, graphs, tables and diagrams.

A plotter consists of an arm that moves across the paper on which the diagram or graph needs to be drawn (refer Figure). A pen moves along the arm, and the arm itself moves relative to the paper. A combination of the two thus provides movement along the horizontal and vertical axes.

Flat-bed Plotter

Flat-bed Plotter

In some plotters, the paper is held stationary while the arm and the pens move over it. This is called a flat-bed plotter. In the other type of plotter, the paper is wrapped around a drum and anchored at both ends. The drum rotates while the pen moves laterally along a fixed rail. This is called a drum plotter.

To draw clear, high-quality diagrams, a plotter needs high-quality pens with special inks of different colors.

A plotter can be connected to a PC through the parallel port. A plotter is more software-dependent than any other peripheral, and needs much more instructions than the printer for producing output.

Plotters are used in applications like Computer Aided Design (CAD) which require high-quality graphics on paper. Many of the plotters now available in the market are desktop models that can be used with PCs. Businesses typically use plotters to present an analysis in visual terms (bar charts, graphs, diagrams, etc.) as well as for engineering drawings.