Our findings together suggest that the formation of a square array at a 𝑄 𝐼𝐼 𝑃 interface represents the thermodynamically preferred arrangement, rather than a pathway-dependent kinetically trapped state, and is adopted spontaneously when appropriate lipids are allowed to self-assemble at an interface in excess hydrating conditions. This property suggests widespread application to different processing methods (dip coating, spin coating, spray), different surfaces and interfaces, and different technological contexts that can exploit the 2D periodicity observed.