Optical Dance Postcard. Op Art.
Op art, also known as optical art, is a method of painting concerning the interaction between illusion and picture plane, between understanding and seeing. Op art works are abstract, with many of the better known pieces made in black and white. When the viewer looks at them, the impression is given of movement, hidden images, flashing and vibration, patterns, or alternatively, of swelling or warping. Wow.
This postcard works horizontally as well as vertically.l