A one-parameter model has been derived by A. Sagiv and P. Stroeve for diffusion through crystalline monolayer and multilayer Langmuir-Blodgett films (J. Colloid Interface Sci. 204, 173 (1998)). The model can describe well a number of experimental observations. The parameter that is needed for the model, the activation rate constant (k), is obtained by fitting the experimental data. It is shown in this letter that the parameter can be calculated independently; hence, the model can be predictive. Examples for predictions are given.