Abstract: Disclosed is a roll-fusing apparatus comprising a heated fusing roller and a pressure roller which form a roller gap therebetween. The shape of the non-cylindrical roller core and the coating of the pressure roller makes it possible to fuse the toner images on copy supports which remain free of wrinkles after passing through the roller gap. In addition, duplication of the copy image does not occur up to DIN A1 size copies. The roller core and the coating of the pressure roller, comprising a silicone elastomer coating and a shrunk-on tubing have varying thicknesses over the length of the roller. As a result, the speed of passage of the copy support at the edges of the roller gap is modified, compared with the speed of passage obtained with a pressure roller having a cylindrical roller core and a cylindrical coating.