Paint is most often a combination of pigment, binder, and solvent. Pigment is the colored portion of the paint. It is often a finely ground material that is either found in nature or artificially produced. Binder holds the individual grains of pigment together. In oil paint, the most common binder is linseed oil, which typically dries to the touch in about one week. The binder in most acrylic paint is an acrylic resin; the binder in watercolor paint is a natural resin called gum arabic. Solvent is a liquid that thins the paint. The most common solvent in oil painting is turpentine. Water is the solvent for acrylic emulsion and watercolor paints.