Files with the .PRN extension contain contents, such as text and images, which are ready for print, as well as printing settings, such as the number of pages, ink type, and printing method. It is a format quite similar to PostScript, and is usually created when the printing command is executed on a file.

PRN files can be printed using many different operating systems – as long as the relevant software supports the format. In the Mac OS X operating system, the file icon simply needs to be dropped onto the printer icon on the desktop, while in Microsoft Windows one can choose Microsoft Office Document Imaging in the file context menu, as long as the version supports the format. If a printer is installed, one can also use the Windows command line.