When a gloss application sheet is conveyed through a nip formed between a first nip formation member and a second nip formation member pressing against each other, the gloss application sheet is sandwiched between the first nip formation member and a recording medium simultaneously conveyed through the nip. The gloss application sheet includes a first contact surface contacting the first nip formation member and a second contact surface disposed opposite the first contact surface for contacting the recording medium. The first contact surface has a reduced adhesive force compared to the second contact surface.