A technique first used in the fifth century by Indian and Chinese Buddhists, oil painting began gaining mainstream popularity in the 15th century, and by the height of the Renaissance had almost completely replaced tempura paints in use and popularity. Because oil paints are the combination of bright pigments and a drying oil, like linseed, oil paint remains wet much longer than other media, allowing the artist to alter the color and texture of the work more easily. However, this means that a painting is generally not dry enough to varnish for up to a year. In fact, because oil paints dry from oxidation and not evaporation, art historians do not consider paintings completely dry until 60 to 80 years have passed.