AbstractFrom a study of the melting behaviour of binary mixtures of glycerides it is possible to predict the properties of some of those fats and oils which contain such glycerides. The results can be useful in margarine formulation, dry fractionation, and solubility problems connected with the preparation of novel fat blends.The phase behaviour of six binary mixtures of palmito‐oleo triglycerides has been studied. The techniques used included the microscopical observation of melting behaviour, X‐ray powder photography, and differential thermal analysis. In two of the systems, particularly the mixture of 2‐oleodipalmitin and 1, 3‐dioleopalmitin, evidence was found of favourable steric factors leading to closer association of unlike molecules at about 50% concentration. This fact can be used to explain certain phenomena in fat systems such as mixtures of palm oil and lard which contain significant amounts of these two glycerides. ‘Graininess’ and enhanced crystallisation at certain concentration levels are two such phenomena.