The third in a series of papers on fatliquoring presents the results of a laboratory study of the effects of oil level, degree of vegetable mordanting, and degree of neutralization of the stock on the physical properties of chrome side upper leather. The concept of an average side to minimize the inherent variability between and within hides was again used as a sampling base in designing a factorial experiment. It was found that the oil level siginificantly influenced the temper, tongue tear strength, and mellowness of the leather. Degree of vegetable mordanting influenced the tongue tear strength and mellowness. No difference in effects on physical properties was found between neutralization levels.