The original intention is to compensate the roll body due to its own weight caused by the sagging method. Numerically, it is the difference between the diameter on the cross section of the center of the roller and the diameter on the end face. The press rolls and calender rolls on the paper machine need to have medium and high heights on the rollers in order to keep the pressure in the nip of the roll evenly distributed and compensate for deflections caused by deflection.