ESC/P
ESC/P, short for Epson Standard Code for Printers and sometimes styled Escape/P, is a printer control language developed by Epson to control computer printers. It was mainly used in dot matrix printers and some inkjet printers, and is still widely used in many receipt printers. During the era of dot matrix printers, it was also used by other manufacturers (e.g. NEC), sometimes in modified form. At the time, it was a popular mechanism to add formatting to printed text, and was widely supported in software.
Derivation
ESC/P derives its name from the start of the escape sequences used, which start with the escape character ESC (ASCII code 27). As an example, ESC E will switch to printing in bold font, while ESC F switches off bold printing. The ESC/P control codes are sometimes also referred to as Epson LQ codes, as they were made popular by the Epson LQ series of dot matrix printers, even though ESC/P was introduced long before LQ printers.
Variants
There are several variants of ESC/P, as not all printers implement all commands.
Epson refers to a more recent variant of ESC/P as ESC/P 2. ESC/P 2 is backward compatible with ESC/P, but adds commands for new printer features such as scalable fonts and enhanced graphics printing.