Wetting Theory discusses the numerous practical applications of wetting, such as preparing self-cleaning surfaces, manufacturing artificial blood vessels, and developing new lubricants and nonadhesive dishes. As part of Wetting: Theory and Experiments, Two-Volume Set, this volume provides new, critical insights into the theory of wetting. Chapters are arranged to allow readers to follow the development of a suggested approach (static and dynamic properties of wetting) and how these tools are applied to specific problems. Main attention is given to nanoscale wetting (nanodrops on solid surfaces, liquid in the nanoslit) on the basis of microscopic density functional theory and fluid dynamics on solid surfaces on the basis of hydrodynamic equations. Aimed at engineers, physical scientists, and materials scientists, this volume addresses the key areas of wetting, providing invaluable insights to the field.