There have been multiple reports over the last 3 decades that stimulus quality and word frequency have additive effects on the time to make a lexical decision. However, it is surprising that there is only 1 published report to date that has investigated the joint effects of these two factors in the context of reading aloud, and the outcome of that study is ambiguous. The present study shows that these factors interact in the context of reading aloud and at the same time replicate the standard pattern reported for lexical decision. The main implication of these results is that lexical activation, at least as indexed by the effect of word frequency, does not unfold in a uniform way in the contexts reported here. The observed dissociation also implies, contrary to J. A. Fodor's (1983) view, that the mental lexicon is penetrable rather than encapsulated. The distinction between cascaded and thresholded processing offers one way to understand these and related results. A direction for further research is briefly noted.