For coloring book fans partial to optical brain-teasers — 29 triad designs that play tricks with your eyes. The versatile design modules include small triads inside larger ones, triads with holes in the center, triangular triads centering around a star, and many other illusions. Add color to the reality-defying shapes and voilà! Dover Original.
Op Art Coloring Book by Jean Larcher Color these 30 original designs to make the interlocking rings, cubes, and other shapes stand out. Some visual illusions will even seem to move back and forth.
Visual Illusions Coloring Book by Spyros Horemis Beware, the designs herein may boggle your mind and confound your eyes. Does the cube go in or out, is the line straight or curved? You'll have fun deciding which while coloring them at the same time. 32 designs.
