Fredrix - Powdered Marble - 4 Lbs. - Fredrix Powdered Marble is a Ph neutral Basic Calcium Carbonate used in making acrylic modeling paste, glue base gesso, and all water and oil dispersed paints. Powdered marble dust creates a very fine textured ground. When added to acrylic gesso it will increase absorbency and tooth. Fredrix has been creating their priming and sizing products for over 140 years and they are made of the finest materials.