It is a yellow gelatinous pasty soap with use in bleaching and cleaning and as a compound of some varnishes.
Often the soap is pretreated with formaldehyde and maleic anhydride.
[1] Resin soap is made by reacting resin acids in wood with sodium hydroxide, as a byproduct of the Kraft process for manufacturing wood pulp.
Acidification of the resin soap produces tall oil.
Pine soap is refined from resin soap via tall oil by acidification, refining and resaponification.