1784 c. 48 §11 Any maker of yellow, brown or rosin soap.
1867 A. Ott ii. iii. 93 Experience has proved that a much better product is obtained by first producing a tallow soap, and afterwards mixing the rosin soap with it.
1960 34 14 Hercules looked into the possibilities of using rosin soap as an emulsifier in the production of synthetic rubber.