<human>:  What is the difference between oil paints and watercolors?
<bot>: The main difference between oil paints and watercolors is in their composition. Oil paints use a combination of pigments bound with a drying oil, such as linseed or safflower oil, while watercolors are artist quality pigments suspended in a water-soluble binder such as gum arabic or glycerin. Oil paintings require a longer drying time than watercolor paintings as the drying agents have to evaporate from the painting before the paint is fully set. The nature of oil paints also gives a more matte and velvety finish compared to the semi-transparent and delicate finish of watercolors.