Op Art is an abstract style of art that uses optical illusions to give the impression of movement, hidden images, flashing and vibrating patterns, or of swelling or warping. For this unit, students discussed and identified the illusions in several artworks (by Victor Vasarely, Akiyoshi Kitaoka, Bridget Riley, Charles Allen Gilbert, and the woman and man playing saxophone illusion). Depending on the grade, I have different versions of the project with specific steps. For 6th grade I have them create Op Art Cones. For 7th grade, students create Op Art Forms which is a bit more organic. For 8th grade, I have students create Op Art Spheres or Vortexes (central vortex, black hole, and curly vortex). As an extension, students can do optical weaving, op art cubes, or op art staircase. These projects are a fun way to introduce or reinforce value gradation techniques to make work look more 3D or realistic. It teaches students how curved lines can imply volume and movement. It also introduces or reinforces the concept of pattern. For the vortexes and forms, students use colored pencils. For the spheres and cones students use sharpies and then color pencil on top to create the value gradation and highlights.