Structured latex coatings find such applications as specialty paints, micro- and ultra-filtration membranes, templates for synthesizing inorganic complementary structures, and embedding media for whole-cell based bioreactors. to control well the microstructure and other properties of the final coatings requires understanding the film formation process that transforms a deposited layer of colloidal particles of polymer into a coherent solid coating as it dries, usually in air. This process cannot be visualized by light microscopy techniques when the latex particles are a few hundred down to a few tens of nanometers in size, as is normally the case. Conventional electron microscopy requires too high vacuum for liquid samples to survive. Environmental scanning electron microscopy tolerates modest partial pressure of solvent but is limited to a coating’s top surface and at low resolution. What is needed is to observe the interior of a drying, hydrated coating at nm-resolution. Cryo-SEM is a powerful means of studying microstructure evolution throughout a coating’s thickness in the wet and moist stages of film formation.