Abstract: A dental impression composition is formulated from a hydrogenated wood rosin, petrolatum, aluminum powder and talc and includes the following characteristics: (1) good plastic flow at mouth temperature to provide adequate working time with low flow at room temperature; (2) good heat and light stability which affords good shelf life with no change in flow properties; (3) flow properties not changed during extensive heating and sterilization during preparation for application on the dental tray; (4) sufficient, but not excessive adhesion strength so that the composition adheres to the tray but not to the patient's wet tissues; and (5) low thermal-expansion coefficient so that there are no dimensional changes as the impression is cooled from mouth temperature and (6) good definition of detail.