The manufacture of blue mottled soap is a difficult operation. In making soap by the cold-process melt 6(3 lb. palm kernel oil and 33 lb. cottonseed stearin or tallow by a very gentle heat and bring the mixture to a temperature of 100 P., then stir thoroughly, and, while stirring, pour in a caustic soda lye of 65° Twaddell, at about 70° F. very slowly, taking care that it is well amalgamated. The amount of lye to be used varies from 70 lb. to 90 lb. When the ingredients have been thoroughly crutched together, pour into a frame. Now mix in a shallow trough 2 lb. of ultramarine (washing blue) with some oil until it forms a cream. With a wooden frame long enough to reach the bottom of the soap frame, the blue may be disseminated through the soap. Dip the wooden frame into the blue and place it in the soap, moving it from side to side until the soap is sufficiently mottled; then cover up the soap frame and allow to stand for three days, when the soap may be cut up.