Vegetable gum produced from the extraction of various species of Acacia (the best type coming from Senegal). It has various uses, in particular, as an adhesive and as a binder in both artistic techniques and in restoration. In artistic terminology, it is the most commonly used gum for its excellence. It melts in water, even if cold. In painting, among other things, it serves as a binder for watercolour, gouache and tempera and as a mordant for gilding.