In portrait mode, text characters travel out of the printer from the top of the character to the bottom. It is also possible to switch to this mode using the set print orientation command (GS V). The printer is set to portrait mode by default.
Portrait mode is also referred to as immediate mode printing, because each object that is sent to the printer while the printer is in portrait mode is printed as soon as the object is completed. No two objects may be printed on the same line in this mode because the paper is advanced as each object is completed and printed.
Certain commands are disabled or work differently while the printer is in portrait mode. Exact details can be found with each command’s description.