Coatings, particularly thin films, of polymeric material are produced in accordance with the invention by applying a finely divided aerosol of polymer solution to a substrate and substantially simultaneously applying an energy source to the applied solution to apply the solution. In cases where the polymer is cross-linking, the energy source assists in cross-linking of the polymer. The preferred energy source is a flame that may optionally or desirably deposit material along with the polymer spray. One particular aspect of the invention is directed to production of polyimide films. In accordance with another aspect of the invention, the co-deposition process is used to provide thin polysiloxane coatings on glass and other substrates.