Hydro- hygro- oleo- omni-phobic? Terminology of wettability classification

A variety of expressions used to classify solid surfaces in terms of their wettability by liquids is presented, and their advantages and deficiencies are discussed. In order to create uniform, clear terminology, a three-layer methodology is proposed to describe wettability of smooth, rough, and very rough surfaces. Existing terms are kept as much as possible in the suggested terminology, and their meanings are clearly defined. A new prefix is suggested in order to distinguish the general effect of roughness on the contact angle from its effect in the extreme cases of complete wetting or non-wettability.