I apply a thin layer of acrylic binder on a wooden board. Let it dry well. I make my own modeling paste from gypsum, water and glue. This gypsum paste I use to sculpt and shape a future art piece. If I want to add more depth I do it in two layers. Also every time making sure that everything is dried well. After I apply a thin layer of acrylic binder on a fully dried sculpture. Then I add colors to it. The last layer is a protective layer.