The classic theory of Thomas and Windle has provided a powerful description of the processes involved in Case-II diffusion, in which a sharply defined front of solvent-swollen gel advances into a glassy polymer. We show how some aspects of the Thomas-Windle model can be introduced into a recent formulation by Rossi and coworkers to provide a phenomenological description of the slowing of the advancing front. (C) 2000 Elsevier Science Ltd. All rights reserved.