The Hewlett-Packard Raster Transfer Language (HP RTL) is a subset of the Printer Command Language (PCL) language. It is used to embed true raster images (bitmaps) into plotter files. Modern plotters (like HP DesignJets) are raster devices, so they need a raster-based language. For backward compatibility they also support the HP-GL/2 (formerly HP-GL) vector language, so the HP RTL language is designed for mixing with the HP-GL/2 language.
Further reading
edit- Hewlett-Packard Company, Barcelona Division (September 1996) [1990]. The HP-GL/2 and HP RTL Reference Guide - A handbook for Program Developers - Hewlett-Packard Graphics Language/2 - Hewlett-Packard Raster Transfer Language (draft 2, second ed.). Barcelona, Spain: Addison-Wesley Publishing Company. ISBN 0-201-63325-6. HP Part No. 5961-3526, 5959-9733. Archived from the original on 2017-02-27. Retrieved 2017-02-28.