Refined techniques and a simple apparatus for producing thin (300–1300 A.) polymer films on glass slides from appropriate polymer solutions are described. A film thickness reproducibility of ±25A. can be achieved without difficulty. The polymers investigated included Formvar 15/19E, Parlodion, VYDR blend B-7, and Cyanocel. Data are presented which show the effect on film thickness of a drain period for the glass slide just above the polymer solution, the residence time of the glass slide in the polymer solution, the nature of the solvent, the concentration of the polymer solution, the temperature, and the nature of the polymer. The results show that the reproducibility of polymer film thickness and the uniformity of the films is higher as the thickness of the film decreases (below about 1000 A.). Film casting conditions which favor a rapid departure of the solvent from the polymer film (such as elevated temperature, dilute solutions, and solvents of high volatility) yielded a high reproducibility in film thickness and an excellent film uniformity.