Another approach to studies of aggregation processes is organization via external stimulus. Floating layers on an air-water interface, while compressed, serve as an excellent model of gradual organization process, often yielding organizational degree unachievable in any other method, leading to interesting properties. Upon BODIPY-C18 compression, first surface pressure rise happens at trough area corresponding to 140-150 Å2 /molecule. This value is sufficiently small, considering the revolution circle of a bottom projection of the molecule is slightly above 140 Å2 . As indicated by a layer compressibility function [Equation 2], collapse happens at the isotherm bend at a relatively low surface pressure of 3.7 mN/m and area of 120 Å2 /m.