A method of forming an overcoat layer. The method comprises providing a substrate having an imaging structure formed thereon, the imaging structure comprising (i) a charge transport layer and a charge generating layer, or (ii) an imaging layer comprising both charge generating material and charge transport material. An overcoat composition is deposited on the imaging structure, the overcoat composition comprising a charge transport molecule, a fluorinated building block, a leveling agent, a liquid carrier and optionally a first catalyst. The fluorinated building block is a fluorinated alkyl monomer substituted at the and positions with a hydroxyl, carboxyl, carbonyl or aldehyde functional group or the anhydrides of any of those functional groups. The overcoat composition is cured to form an overcoat layer that is a fluorinated structured organic film, the curing comprising treating an outer surface of the overcoat composition with at least one cross-linking process. The crosslinking process forms a cross-linking gradient in the overcoat layer. If the overcoat composition comprises the first catalyst, there is an insufficient amount of the first catalyst to fully cross-link the overcoat layer.

There is provided a method for electrostatic printing comprising providing a print substrate having a layer comprising a polymeric material, the layer comprising a polymeric material having thereon a surface layer comprising an aminofunctional silane; carrying out an electrostatic printing process to transfer an ink onto the surface layer comprising the aminofunctional silane. Also disclosed herein are print substrates producible by the method, and print substrates for use in the method.