Results of studies of the effects of various factors on film yellowing, the mechanism of yellowing, its inhibition, and isolation and characterization of the yellow constituents are reported.Yellowing appears to be a side reaction unrelated to the drying process, but colorless precursors of the yellow compounds are formed as a result of an oxidative process.The formation of the yellow compound was postulated as taking place by the interreaction of the colorless precursors in some type of condensation. Low‐molecular‐weight aldehydes prevented yellowing, possibly by acting as substitutes for some reactant in the condensation reaction.

Summary An improved “synthetic” method of determining solubilities has been described which combines simplicity with accuracy. Saturated fatty acids with even numbers of carbons from C6 to C18 and oleic, linoleic, and linolenic acids, their methyl esters, their simple triglycerides and their corresponding alcohols have been prepared in purified form. The solubilities in acetone of their most stable forms have been determined from ordinary room temperatures down to about −70°C. or to temperatures where they are only slightly soluble. The precipitation of unstable polymorphs from solutions was observed in the case of palmityl alcohol.