Just an Illusion
What do we see when we look at the drawing on the stamp from Austria (1981) above? Several artists, notably the Dutch ‘master of optical illusion’ Maurits Escher, have incorporated into their designs certain impossible features that cannot exist in three-dimensional space. These include the ‘impossible cube’ on the stamp above, inspired by his designs and the ‘impossible triangle’ by the Swedish artist Oscar Reutersvärd, shown on the first of the three stamps from Sweden (1982) in the continuation of this article.