Editing Op art (section)

=== Black-and-white and the figure-ground relationship ===
Op art is a perceptual experience related to how vision functions. It is a dynamic visual art that stems from a discordant [[figure–ground (perception)|figure-ground]] relationship that puts the two planes—foreground and background—in a tense and contradictory juxtaposition. Artists create op art in two primary ways. The first, best known method, is to create effects through pattern and line. Often these paintings are [[black and white]], or shades of gray (''[[grisaille]]'')—as in Bridget Riley's early paintings such as ''Current'' (1964), on the cover of ''The Responsive Eye'' catalog. Here, black and white wavy lines are close to one another on the canvas surface, creating a volatile figure-ground relationship. [[Getulio Alviani]] used aluminum surfaces, which he treated to create light patterns that change as the watcher moves (vibrating texture surfaces).  Another reaction that occurs is that the lines create after-images of certain colors due to how the retina receives and processes light. As [[Goethe]] demonstrates in his treatise ''[[Theory of Colours]]'', at the edge where light and dark meet, color arises because lightness and darkness are the two central properties in the creation of color.{{Citation needed|date=October 2009}}