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

Plastic

A plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...

 as a medium.

Artist

Artist

An artist is a person engaged in one or more of any of a broad spectrum of activities related to creating art, practicing the arts and/or demonstrating an art. The common usage in both everyday speech and academic discourse is a practitioner in the visual arts only...

 Roxy Paine created a sculpture

Sculpture

Sculpture is three-dimensional artwork created by shaping or combining hard materials—typically stone such as marble—or metal, glass, or wood. Softer materials can also be used, such as clay, textiles, plastics, polymers and softer metals...

-making machine: a large metal contraption that oozed acrylic on to a conveyor belt

Conveyor belt

A conveyor belt consists of two or more pulleys, with a continuous loop of material - the conveyor belt - that rotates about them. One or both of the pulleys are powered, moving the belt and the material on the belt forward. The powered pulley is called the drive pulley while the unpowered pulley...

 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

San Francisco Museum of Modern Art

The San Francisco Museum of Modern Art is a modern art museum located in San Francisco, California. A nonprofit organization, SFMOMA holds an internationally recognized collection of modern and contemporary art and was the first museum on the West Coast devoted solely to 20th century art...

 in January 2001.

Plastic is also frequently used in found art

Found art

The term found art—more commonly found object or readymade—describes art created from undisguised, but often modified, objects that are not normally considered art, often because they already have a non-art function...

 and other types of art

Art

Art is the product or process of deliberately arranging items in a way that influences and affects one or more of the senses, emotions, and intellect....

 made from commodity materials. Plastic containers are useful in papier-mâché

Papier-mâché

Papier-mâché , alternatively, paper-mache, is a composite material consisting of paper pieces or pulp, sometimes reinforced with textiles, bound with an adhesive, such as glue, starch, or wallpaper paste....

for building frames.