The relation between permeability and sorptivity has not received much attention in the literature of porous materials. Therefore the paper of Benavente et al. (Benavente et al., 2015) is a valuable contribution, both for its theoretical analysis and for providing new data on these properties in a test set of rocks, mostly carbonates. In this Discussion we make some related observations on the topic. We employ the quantities and notation of (Benavente et al., 2015), except that we use the sorptivity S rather than the water absorption coefficient C by capillarity” in describing imbibition. The two are simply related since S = C/ρw where ρw is the density of water.