The loading cycle of many (perhaps most) commercial adsorption and ion exchange operations involves a favorable isotherm. Concentration fronts for favorable isotherms approach a constant pattern for long bed lengths, and most industrial adsorption and ion exchange operations use sufficiently deep beds that the constant-pattern conditions are approached. Once a constant pattern is established. the region around the front can be analyzed using conventional methods developed for continuous absorption/stripping operations, but the location of the feed and withdrawal points must be assumed to move down the bed at the same rate at which the front moves. Using this approach, the constant-pattern front can be calculated for any shape of constant-pattern isotherm. The dimensionless distance in the bed is expressed in terms of transfer units, and the shape of the front can be evaluated graphically even when the relations can not be integrated analytically. This procedure is illustrated for binary ion exchange isotherms. In the simplest cases, exchange of ions with like charge, the integration can be performed analytically. For other cases, numerical and graphical solutions are illustrated.