The majority of dermatological textbooks, even some newer ones, describe pastes as semisolid, stiff preparations containing a high proportion of finely powdered material, such as zinc oxide, titanium dioxide, starch, kaolin, and talc, incorporated at relatively high concentration in a suitable vehicle.∗ These vehicles are by the majority lipophilic or greasy, and the properties of the pastes are globally described as cooling, drying, exudate absorbing, and protecting.1-7 In a recent publication, a critical review of the evidence available to assert these statements was conducted.8 It was concluded that “serious doubts must arise from the available explanations and the various formulas of pastes and their absorptive features.” Detailed investigations showed that first the powders themselves presented very different absorptive features, and further that two-phase, lipophilic pastes did not absorb moisture independently from the inner phase (powder). On the contrary, three-phase pastes consisting of an hydrophilic two-phase emulsion and a high concentration of powder (inner phase) showed considerable water uptake. It was concluded that not only the “active component(s)” of a paste, that means the powder itself or the mixture of several powders, but also the vehicle used to manufacture the paste is of major importance for the final effect on the skin. Based on these statements, a classification of the pastes was proposed8 (Figure 22.1).