What is the cause of dark spots that sometimes appear on the paper of drawings and paintings? Reddish-brown spots are known as "foxing", caused by mold or the deterioration americanflagclipart of the metallic impurities left in the paper from the manufacturing process. Other colors of spots may be one of many types of mold damage. Mold spores are everywhere in the environment, and mold thrives on cellulosic materials, especially in conditions of high humidity (above 65% of relative humidity). Keeping artworks out of high humidity areas like bathrooms or exterior walls, can help reduce the development of such stains. If I have a work of art on paper that appears to not be flat, should I be concerned? Paper is hygroscopic, reacting to changes in climate by expanding when it is humid and contracting when it is dry. A gentle undulation in the paper called "cockling" occurs under these conditions, especially with larger works. This may impair the work aesthetically americanflagclipart as well as cause mediums such as gouache americanflagclipart to crack or flake as it is unable to expand and contract as the paper itself does.

One Thing After Another explores the relationship of printmaking to the proliferation of serial imagery in the contemporary period. Classic serial print projects from Pop art and Minimalism are juxtaposed with works from 1980s and 1990s. Artists included range americanflagclipart from Andy Warhol, Roy Lichtenstein, Ellsworth Kelly, and Brice Marden to Rosemarie Trockel, John Armleder, Yukinori Yanagi, and Anish Kapoor. Pop and After juxtaposes major works americanflagclipart of the 1960s by American and European artists, which focus on mass media and the iconography of consumer culture, with works by younger creators of the 1980s and 1990s that extend and twist the stylistic and social concerns of Pop art. Artists included range from Andy Warhol, Claes Oldenburg, and Roy Lichtenstein to Jeff Koons, David Hammons, and Damien Hirst.