Image forming system and apparatus with different printing modes for different numbers of printing sheets

An image forming apparatus comprising:

• an image forming portion for forming a toner image on a recording material;
• and
• a heating fixing portion for heating and fixing the toner image on the recording material,
• wherein for a printing on a small size sheet having a width smaller than a maximum processable width of said image forming apparatus, said apparatus is operable in a first small size sheet printing mode, in which a number of continuously printable sheets is not limited, and a second small size sheet printing mode in which a number of continuously printable sheets is limited and in which an output number per unit time is greater than that in the first small size sheet printing mode,
• wherein when a new printing command is inputted during execution of a current printing job in the first small size sheet printing mode, a new printing job is started after completion of the current printing job without a rest period, and
• wherein when a new printing command is inputted during execution of the current printing job in the second small size sheet printing mode, a new printing job is started after the completion of the current printing job, with a predetermined rest period between the completion of the current printing job and the start of the new printing job.