<human>:  When did the first oil painting appear?
<bot>: The first oil painting was probably done in the 12th century, by a painter named Giotto di Bondone. Giotto was the first person to paint with oil paints, which are made from linseed oil and other ingredients. Oil paintings have been around for thousands of years, but they were primarily used for religious purposes. In the 14th century, oil painting became more widely used for secular purposes, and artists like Leonardo da Vinci began experimenting with oil paints.