Abstract The shape of nonlinear elution peaks was studied experimentally in various chromatographic modes and a wide sample size range encompassing the case where the distribution isotherm curvature is the prevailing factor of band broadening. It is shown that as sample size is varied, the tailing part of all peaks adjoins a common curve that can be fitted with an exponential function whose parameters are independent of mobile phase linear velocity and stationary phase particle size. The effect of solute capacity factor on these parameters was also investigated. These findings provide valuable help for the optimization of linear velocity, particle size, as well as sample size in preparative liquid chromatography under mass overload conditions.