When choosing a watercolour, you may find information that the binder in a particular range is natural Gum Arabic.
This component helps to distribute the pigment on the working surface and (most importantly) binds the pigment to the paper.
GUM ARABIC is a hard, transparent resin composed of the dried sap of various species of acacia trees. Originally collected from Acacia nilotica, Gum Arabic is now extracted mainly from two related species, namely Acacia senegal and Vachellia (Acacia) seyal. Under modern conditions, resin is harvested commercially from wild trees mainly in Africa (from Senegal to Somalia), although West Asia (including Arabia) was a major source of Gum Arabic in ancient times. Sudan accounts for about 80% of the world’s production. Another name for acacia resin is soluble gum.
INTERESTING FACT
Soluble gum is a food additive and has the code E414.
USE IN ART
Gum Arabic has been used for centuries as a binder for glue paints – watercolour painting – because it dissolves easily in water. One part of Gum Arabic powder, dissolves in four parts of distilled water to make the glue solution needed to mix with pigments. The pigment is in the gum as a fine suspension, resulting in a watercolour paint.The water acts as a diluent and helps transfer the colour to the paper.
Using Gum Arabic as a medium for watercolour reduces the absorption of the ink into the paper and thus makes the drawing brighter.
By adding Gum Arabic to the paint solution, we increase the transferability of the colours and slow down the drying time. These properties are very helpful when working in the raw.
