Organosilica coatings obtained by the versatile sol–gel process are finding applications of great environmental and economic impact, such as in the case of new antifouling and anticorrosive paints entirely devoid of harmful effects. Whether as undoped ORMOSIL (organic modified silicates) or as doped silica/polymer composites, potent nanomaterials are obtained in which chemical and physical protection of the coated surfaces often accompany other functions. We investigate the principles behind this remarkable field of nanochemistry.