​The Secret to Great Lime Finishes: Making Lime Putty ​The journey to high-quality lime plaster and mortar starts with the patient preparation of lime putty, often called fat lime for its rich, creamy texture. ​Mix & Wait: After mixing your hydrated lime (or slaking your quicklime) with water to that beautiful, whipped consistency, the hard part is waiting! You need to allow the lime to crystallize and mature. While some projects use it sooner, for the best results, let it rest under a layer of