Rublev Colours Gum Arabic or gum acacia is a water-soluble gum derived as an air-hardened, gummy exudate flowing naturally from or obtained by incision of the trunk and branches of Acacia Senagal. It is used to make watercolor and tempera paint, ink, adhesives and as a binding medium for marbling colors. Our gum is the actual exudation of the acacia tree in the form of pebbles without any additional processing.
The gum is spheroidal, oval, or reniform pieces (tears) of varying diameter from about 1 to 3 cm., yellowish white, yellow, or pale amber, sometimes with a pinkish tint, friable, opaque, frequently with a cracked surface, easily broken into irregular, whitish or slightly yellowish angular fragments with conchoidal fracture and a glassy and transparent appearance. In the center of unbroken tears there is sometimes a small cavity.
Does not contain starch as is indicated by the Iodine Test: The powdered gum is not colored blue (indicating absence of starch) or red (indicating absence of dextrin) by the iodine test solution.
It is almost completely but very slowly soluble in twice its weight of water, leaving only a very small residue of vegetable particles. The liquid (mucilage) obtained is colorless or yellowish, dense viscous, adhesive, translucent and weakly acidic to blue litmus paper.
Gum arabic is used in the food industry to fix flavors and as an emulsifier, to prevent the crystallization of sugar in confectionery products, as a stabilizer in frozen dairy products; its viscosity and adhesive properties find use in bakery products, and as a foam stabilizer and clouding agent in beer. In the pharmaceutical industry gum arabic is used as a stabilizer for emulsions, binder and coating for tablets, and as an ingredient in cough drops and syrups. In cosmetics it finds use as an adhesive for facial masks and powders, and to give a smooth feel to lotions.
100% pure exudation
Yellowish white, yellow or pale amber
Shape and Size:
Spheroidal, oval or reniform pieces (tears) of varying diameter from about 1 to 3 cm diameter
Odorless, tasteless and adheres to the tongue.
Soluble in twice its weight of water. Practically insoluble in ethanol (96%) and in ether.
Specific Optical Rotation:
Range of -26° to -34° A 10% w/v solution in water is laevorotatory.
Kjeldahl nitrogen content of 0.27-0.039
Loss on Drying:
When dried at 100° to 105° C. loses not more than 15% of its weight.
Gum acacia consists principally of arabin, a compound of arabic acid with calcium and varying amounts of the magnesium and potassium salts of the same acid being present.
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.
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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.
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