Gypsum Pigment

Gypsum is a natural white pigment ground from gypsum, a soft mineral made of hydrated calcium sulfate. It produces a soft, bright, slightly cool white with a smooth, matte finish. In glue and water based binders it gives a clean, absorbent white; in oil it becomes largely transparent.

In use, Gypsum is the traditional base for Italian style gesso grounds on panels, giving a smooth, brilliant white surface that is ideal for tempera, gilding and fine oil painting. It can also be used as an extender and texture builder in tempera, distemper and encaustic. It is lightfast and stable, and unlike chalk it is not dissolved by mild acids, though it is slightly soluble in water over time.

History

Gypsum has been used in painting since antiquity, from Egyptian plasters to medieval and Renaissance panel grounds. In Italy, painters prepared panels with layers of gesso grosso and gesso sottile, both made from gypsum bound with animal glue, as described by Cennino Cennini in the early 15th century. These brilliant white grounds sit beneath many of the great Italian panel paintings of the 13th to 16th centuries.

Pigment Information

Pigment Type: Natural (Inorganic) calcium sulfate mineral
Source: Natural gypsum (CaSO₄·2H₂O), ground
Origin: U.S.A.
Suitable Mediums: Gesso, Glue / Distemper, Tempera, Casein, Watercolor, Gouache, Encaustic, Acrylic; in oil as a transparent extender
Lightfastness: Excellent
Opacity: Semi-opaque in water based media, transparent in oil
Other Names: Gesso, Selenite, Alabaster White, Terra Alba, Calcium Sulfate White
Color Index Code: PW25

Health and Safety

For art use only. Not for cosmetic, food or children's use.
Keep out of reach of children and pets. Do not eat, drink or smoke while working.
Avoid creating or breathing dust. Work in a ventilated area and wear a NIOSH approved dust respirator (P100 or better) when handling dry pigment.
Wear gloves and eye protection. Wash hands and work surfaces after use, and never rinse pigment into drains.
Do not spray apply, sand or burn.
If swallowed or if you feel unwell, contact a poison control center (U.S. 1-800-222-1222) or a doctor.
Safety Data Sheet available on request.

Caution: Natural earths and minerals contain crystalline silica (quartz). Breathing the dust over long periods can cause serious lung disease (silicosis) and lung cancer. Always use a dust respirator with the dry pigment.