The quantity of raw (unsulfated) mineral oil which can be advantageously incorporated into sulfated fatty oils varies greatly acording to tannage and degree of lubrication. In this work, a series of soluble (water miscible) oils were prepared containing a constant ratio of emulsifier to raw oil in which the composition of the latter varied from straight cod to all mineral oil. Results showed that as the mineral oil is increased, emulsification is slightly enhanced. A high concentration of the (less reactive) mineral oil reduces the combined oil content. As mineral oil replaces raw fatty oil less oil deposits in the flesh division, more in the grain division and more oil penetrates the corium. An increase in mineral oil in the total fatliquoring oil increases, then decreases tear strength and stretch. Raw mineral oil softens leather better than raw cod oil. -- AATA