EMF (Enhanced MetaFile) and raw are terms for spool file formats used in printing by the Windows operating system . When a print job is sent to the printer , if it is already printing another file, the computer reads the new file and stores it, usually on the hard disk or in memory , for printing at a later time. Spooling allows multiple print jobs to be given to the printer at one time.
The EMF format is the 32- bit version of the original Windows metafile (WMF) format. The EMF format was created to solve the deficiencies of the WMF format in printing graphics from sophisticated graphics programs. The EMF format is device-independent. This means that the dimensions of a graphic are maintained on the printed copy regardless of the resolution in dots per inch of the printer. In a network, the smaller file size of the EMF format reduces network traffic. EMF is the spool file used by the Windows operating system.
A raw spool file is a one that is sent to the Windows spooler unprocessed (which is why it's called "raw"). The raw file is used to send Postscript commands to a Postscript printer. The Postscript commands are understood by the printer, but are just plain data to the Windows spooler. The raw format is device-dependent and slower. If printing problems occur while using the EMF format, they can sometimes be fixed by simply changing the format to "raw" in the printer Properties.