Gum Arabic, or gum acacia, is the sap inside the acacia trees living in Senegal, Sudan, Somalia, west Asia and other parts of sub-Saharan climates. The sap of the trees drip through cuts in the bark, then hardens on the outside. Once hardened, gum can be taken from the tree and can be used for a variety of different purposes. If you need gum Arabic for a project, you can find it a number of baking supply shops, art stores or photography supply stores.
The sap from the acacia tree is made from a mixture of saccharides and glycoproteins, and is used extensively in cooking and baking. Both saccharides and glycoproteins are important ingredients in the making of different sugary foods like soft drinks and candy. The syrup that is mixed in soft drinks, chewing gum, cake decorating icings and frostings and gummy candy all use gum Arabic to give foods the perfect consistency and sweetness with an edible gum-like texture.
Gum Arabic is also used as a soluble binder and has the ability to reduce the surface tension in liquids; this plays an important role in fireworks. As binder, gum Arabic binds together the different components in the pressed compositions that make up the firework or other pyrotechnics. With the ability to reduce the surface tension of liquids, gum Arabic increases the fizzle and spray of the fireworks once in the air to create the beautiful explosion it causes.
Gum Arabic is also used extensively in photography, specifically gum bichromate photography. Mixing with either watercolour paints, dry pigments, inks or gouache paints, the gum Arabic permanently binds the colours you choose to the paper. The gum Arabic produces a light-sensitive emulsion to produce the photograph. If gum Arabic is used instead of traditional photography chemicals, a darkroom is not needed and the photos are developed in water rather than developing solutions.
Gum Arabic can also be used to bind, cement and preserve fossils, especially for amateur paleontologists that do not want to spend money on expensive preservation materials and equipment. For broken fossils, the gum Arabic will bind, or simply glue, the broken pieces together easily. The gum Arabic can be poured lightly over the entire fossil to preserve the fossil inside the clear gum. Mix the gum Arabic in spirit alcohol to create a thin and runny liquid, then "paint" the gum Arabic over the entire fossil, or even a rock containing a fossil, to preserve it.