Large differences in permeablility, adsorption, and solubility are found between films made from untreated alkali-refined linseed oil and films made from the oil after heat treatment. The increase in time of heat treatment does not produce so much difference in these film properties as is shown between the untreated and realtively short heat-treated oils. The difference in these properties of films made from oils which have been heat-treated in air and those heat-treated in vacuum is relatively small. The water adsorption of films made from high-acid oils is greater than that of films made from low-acid oils, but the diffusion of moisture through a film is retarded by the metallic soaps formed in high-acid oils so that the permeability to moisture of the high-acid oil films was lower than the low-acid films. The effect of oxygen absorption, with consequent decompostion products in air-dried films, is to lower their water resistance as compared with films which are baked. It is not possible to relate directly the physical and chemical characteristics of a series of oils to the physical properties of films made form these oils because of the large number of variables involved.