AbstractA number of binary systems have been studied, each involving a 1‐monoglyceride. Included was the binary system of 1‐monopalmitin (1P)‐1‐monostearin (1S). Other systems involved 2‐monoglycerides, 1,3‐diglycerides and triglycerides as follows: 2P‐1P, 2S‐1S, PP‐1P, SS‐1S, PPP‐1P, SSS‐1S. A general principle running through the observed behavior is that the more chemically similar the components, the greater is the interaction or solid solution formation. Thus 1P‐1S showed continuous solid solution in both stable and metastable states with “compound formation” in the stable state. The systems 2P‐1P and 2S‐1S showed ॅ (sub ॅ) stability in a single solid solution phase for the range 20‐80% 1‐monoglyceride. The system PP‐1P and SS‐1S showed extensive solid solution formation in an ॅ state but little or none in the stable state. There was essentially no solid solution formation observed for stable states of PPP‐1P and SSS‐1S; experimental limitations made it difficult to draw certain conclusions about the metastable state, but here, too, it is believed, solid solution formation was negligible.