1.Acetostearins were prepared by reacting various proportions of acetic anhydride with a monostearin of 99.2% purity, a commercially available monostearin containing 91.5% monoglycerides, and a technical grade monostearin containing 61% monoglycerides. The last mentioned product was prepared from a completely hydrogenated cottonseed oil. After the removal of unreacted acetic anhydride and acetic acid from the reaction products, the flexibility and melting characteristics were determined.2.All of the acetostearins tested were non-greasy solids at room temperature yet were highly flexible. At a temperature of 22°C. most of them could be stretched more than 800% under the test conditions. Bending tests revealed that some of the products possessed good flexibility even at 4°C.3.The melting characteristics of the products were dependent on the purity of the monostearin used and the degree of acetylation. Some products melted completely below body temperature (37°C.), and others melted at temperatures up to 60°C. The temperature interval over which melting occurred was usually very short (1–3°); however products made from technical grade monostearin melted over a temperature range of 1