In M. Singh and B. L. Anderson, the authors proposed a model based on ratios of Michelson contrasts to explain how human observers quantitatively scale the perceived opacity of transparent surfaces. In subsequent work by B. L. Anderson, M. Singh, & J. Meng, the authors found that this model failed to generalize to other contexts and replaced it with a new, more general model based on ratios of perceived contrasts. M. K. Albert's main experiment aimed to test the model the authors have previously rejected. The authors argue that M. K. Albert's experimental method was flawed and that his experiments did not test either the authors' original model or the authors' subsequent model that replaced it. M. K. Albert failed to provide any account of the data that the authors' model predicts, and he did not provide any theory to explain his own data. The authors conclude that the discrepancy between M. K. Albert's results and all models of transparency results from problems in the methods used in his experiments, not from the shortcomings of extant theory.