Printing apparatus connected to a saddle finisher with image forming controlled based on a transparency of a cover sheet

A printing apparatus connected to a saddle finisher that receives a body sheet and a cover sheet from a printing apparatus, and performs a bookbinding process on a sheet bundle including the body sheet and the cover sheet, the printing apparatus comprising:

• an image forming unit that forms an image on the body sheet and forms an image on the cover sheet, wherein the image forming unit comprises a reversing mechanism that reverses and discharges the cover sheet;
• and
• a controller that control the image forming unit:
• (i) in a case that the cover sheet is a first type of sheet, to form a normal image on the cover sheet after forming the image on the body sheet and to convey the cover sheet on which the normal image has been formed to the saddle finisher without reversing the cover sheet,
• (ii) in a case that the cover sheet is a second type of sheet that has a higher transparency than the first type of sheet and is able to be reversed by the reversing mechanism, to form a mirror image on the cover sheet after forming the image on the body sheet and to convey the cover sheet on which the mirror image has been formed to the saddle finisher by reversing the cover sheet using the reversing mechanism, and
• (iii) in a case that the cover sheet is a third type of sheet that has a higher transparency than the first type of sheet and is not able to be reversed by the reversing mechanism, to form a normal image on the cover sheet after forming the image on the body sheet and to convey the cover sheet on which the normal image has been formed to the saddle finisher without reversing the cover sheet.