Within the 20th century, there came the use of plastics in art.[1] In the latter half of the century, plastic technology advanced so that it was feasible for artists to start using plastic and acrylics as an artwork medium.
ArtistRoxy Paine created a sculpture-making machine "Scumak No. 2":[2] 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.
^Mustalish, Rachel. "Modern Materials: Plastics". Heilbrunn Timeline of Art History. Sherman Fairchild Center for Works on Paper and Photograph Conservation, The Metropolitan Museum of Art. Roxy Paine | Acrylic Art | Plastic Artwork. Retrieved 18 February 2016.