This dry ground natural gypsum (calcium sulfate) is made according to an old process near Siena, Italy. Gesso Oro per Indoratori is quarried and processed in Colle Val d'Elsa, the birth place of Cennino Cennini, in the same locale where he obtained his gesso for "gesso sottile." Gesso (Italian for gypsum) was used since before the Renaissance and mixed with glue size to prepare wood panels and frames for painting and to adhere gold leaf.
Softer than chalk (3 Mohs scale of mineral hardness), its hardness of 1.5 to 2 makes a soft white gesso that is easier to polish to a smooth finish for gilding bases and painting grounds. Calcite or chalk, being a carbonate, effervesces on exposure to acids, whereas gypsum alabaster, when so treated, remains practically unaffected.
Recommended in Cennino Cennini's treatise on painting, Il libro dell'arte (often translated as The Craftsman's Handbook), to make "gesso sottile" for painting grounds. It makes a brilliant white gesso that can take a high polish for gilding. Add to oil colors and mediums as a transparent filler and to give body or in tempera as a white filler.
Natural Pigments is a limited liability company based in Willits, California. We manufacture and distribute rare and hard-to-find materials for fine artists and decorators. We specialize in supplying artists' materials that were used in historical painting since pre-historic times up to and including the nineteenth century.
We constantly search for materials and products of the finest quality so that we can bring them direct to you from the source. To do so, we travel the world to find materials specifically for use by professional artists and decorators. We obtain minerals from mines in Afghanistan, Chile, Russia, Ukraine and Uzbekistan, to name a few places, processing these into natural pigments. We purchase resins, gums and plants from India, Kenya and Malaysia to make natural varnishes and painting mediums.
Our mission is to provide the largest variety of natural pigments, paints and other professional artists' supplies, enabling us to bring you a selection that makes shopping for rare and hard-to-find art materials easy. Our objective is to promote the education and use of these materials among artists by providing detailed information for their employment in encaustic, fresco, oil, watercolor and tempera painting.
This product is shipped from our warehouse in Gretna, NE, USA.
This product is brand new and includes the manufacturer's warranty, so you can buy with confidence.
Please submit your product question using this form. All fields are required.