Abstract: Polyimide film prepared from a precursor solutions of polyamic acid in a solvent can be dried during or following the thermal or chemical conversion step, which produces a polyimide, by adding to the solution a small amount of an alkyl ester of phthalic, terephthalic, or isophthalic acid, casting the solution on a flat surface and heating the solution on the flat surface at about 100.degree.-200.degree. C.; then, removing the resulting partially converted film from the flat surface and heating it, under restraint, to about 200.degree.-375.degree. C., to bring about complete conversion and remove virtually all of the solvent. Polyimide films are useful in various applications where high temperature resistance is required, including composites for aerospace applications and for circuit boards for electronic equipment.