something-fileformat somethingtops application/postscript pstops application/vnd.cups-postscript cupsomatic (constructs complicated Ghostscript commandline to let the file be processed by a "-sDEVICE-s.th." call...) pstoraster (= "postscript interpreter") application/vnd.cups-raster rastertosomething (= "raster driver") something device specific backend Ghostscript at work.... Note, that cupsomatic "kidnaps" the printfile after the application/vnd.cups-postscript stage and deviates it gh the CUPS-external, systemwide Ghostscript installation, bypassing the "pstoraster" filter (therefore also bypassing the CUPS-raster-drivers "rastertosomething", and hands the rasterized file directly to the CUPS backend... cupsomatic is not made by the CUPS developers. It is an independent contribution to printing development, made by people from Linuxprinting.org. (see also http://www.cups.org/cups-help.html)