Making Practice Lime Putty for Fresco Painting

This video from the FrescoSchool.org demonstrates how to prepare "practice lime putty" from common construction Type S hydrated lime powder. Can be used for Lime Wash. Main difference between Construction Type-S Lime and Fresco Lime is it's chemical composition - Type-S Hydrated Lime is manufactured from Dolomitic Limestone (Dolomitic limestone contains 35 to 46 percent magnesium carbonate). Good Lime for fresco painting should contain at least 95% of Calcium Carbonate.