A method is disclosed of three-dimensional (3D) free-form printing for coating free-form objects, the method including: arranging a free-form object in a Langmuir-Blodgett (LB) trough filed with a liquid, the LB trough designed based on a shape of the free-form object; arranging an LB film comprising a plurality of colloidal nanospheres on a surface of the liquid within the LB trough; and draining the liquid from the LB trough to form a self-assemble film of the colloidal nanoparticles on a surface of the free-form object.