, Size: 5 Kg, Particle Size Grades: Ultra-Fine 1–10 µm

The finest whiting for making brilliant white chalk grounds. Our whiting is dry ground from limestone deposits in the Lucerne Valley, California. Dry grinding limestone reduces it to a powder without destroying its particle structure, which is essential in making strong chalk grounds and providing tooth on the surface of the grounds. The larger particle size of our chalk (when compared to precipitated chalk) keeps oil absorption low, which is ideal when adding it to oil paint and mediums. In painting grounds, it makes a durable surface with tooth for egg and casein tempera, distemper, encaustic, and oil paint.

Limestone (calcium carbonate CaCO3) is a type of carbonate sedimentary rock that is the primary source of the material lime. It is composed mainly of calcite and aragonite, which are different crystal forms of calcium carbonate.

The Lucerne Valley limestone district contains enormous high-brightness, high-grade calcite limestone reserves. It lies in the California Transverse Ranges of Southern California and extends for about 40 kilometers along the north slope of the San Bernardino Mountains, overlooking the Mojave Desert. About 5% (12 thousand hectares) of the San Bernardino Mountains is underlain by Paleozoic carbonate rocks. This carbonate stratigraphic section averages about 1,500 meters thick, with white high-grade calcite limestone units ranging from 15 to 30 meters thick.

Add ground calcium carbonate to oil colors and mediums to create textural and bodying qualities to oil paint without affecting the color. Ground limestone has a little color in drying oil, so it can be added to oil paint without affecting the tint of the color.

For a complete explanation of the available particle size grades and their use in artist's paints, please read .