Paintings are the aesthetic products of the practice of painting, which has been a human activity for thousands of years. Paintings are made with pigments that are mixtures of certain chemicals, binders and sometimes other substances. They provide a physical form in which an artist can explore creative expression. Paintings can be created on canvas or another support medium. They can be created using various methods including drawing, painting, printmaking, photography, sculpture, ceramics and many other techniques. Paintings are used in art history to document the history of art movements in visual form. A painting may represent a historical moment or simply express an emotion or idea that continues to live on. Paintings may be created spontaneously without previously forming plans, or they may be executed based on previously composed plans. A painting can have many purposes including representing an idea, selling a product, decorating the wall or simply being an aesthetic object.