Opaline effect pigments by spray induced self‐assembly on porous substrates

Self‐assembling of opaline materials on porous substrates like paper requires a very fast crystallization, which can be realized with highly monodisperse colloids. This opens the possibility of applying effect pigments to such substrates not by spraying the rather large effect pigments themselves, but by spraying their building blocks, which self‐assemble later on. The feasibility of this approach is presented here for monodisperse polymethyl methacrylate (PMMA) spheres. This process tolerates additives used for ink‐jet printing.