A prepared substrate (quartz or polymer such as PET, e.g.) is submerged in a solution of a positively charged polymer, rinsed, dried, and then submerged in a solution of negatively charged clay platelets.
Each cycle of alternating submerging leads to the formation of a single clay-polymer bilayer, and cycles are repeated until the desired number of bilayers is achieved. Bilayers are held together by electrostatic attraction between the polymer and clay layers, which have opposite polarity.