Lime and gauging (gypsum) finish plasters were commonly used during the early to mid twentieth century. While convenient and strong, gypsum does not expand and contract to the same degree as pure lime causing failures that make it incompatible with pure lime based plasters. Our product formulation, based on historic plaster research and material analysis, offers outstanding skim coat plaster performance for fine interior finish work over traditional lime plasters. Weight: 49 lbs