With the 20th century came the use of plastics in art. In the latter half of the century, plastic making technology advanced so that it was feasible for artists to start using plastic as a medium.
Artist Roxy Paine created a sculpture-making machine: a large metal contraption that oozed acrylic on to a conveyor belt that jiggled slowly back and forth. The barely liquid plastic would pile up and solidify. After a few hours, the conveyor belt would move the pile forward and begin a new sculpture. The machine was exhibited at the San Francisco Museum of Modern Art in January 2001.
Plastic is also frequently used in found art and other types of art made from commodity materials. Plastic containers are useful in papier-mâché for building frames.