Watercolor painting to paints that use water-soluble, complex carbohydrates as a binder. Originally (in the 16th to 18th centuries), watercolor binders were sugars and/or hide glues, but since the 19th century, the preferred binder is natural gum arabic, with glycerin and/or honey as additives to improve plasticity and solubility of the binder, and with other chemicals added to improve product shelf life. The term "bodycolor" refers to paint that is opaque rather than transparent. It usually refers to opaque watercolor, known as gouache. Modern acrylic paints use a acrylic resin dispersion as a binder. Watercolor painters before the turn of the 18th
Hand-colouring of photographs finish. Before the paint can be applied, the surface of the print must be primed so that the colours are not repelled. This often includes prepping the print with a thin coating of shellac, then adding grit before colouring. Watercolour paint used in photographic hand-colouring consists of four ingredients: pigments (natural or synthetic), a binder (traditionally arabic gum), additives to improve plasticity (such as glycerine), and a solvent to dilute the paint (i.e. water) that evaporates when the paint dries. The paint is typically applied to prints using a soft brush. Watercolours often "leave a darker edge of color at