Mauritis Cornelius Escher (1898-1972) is a Dutch graphic artist. He created  "tilings," pictures in which shapes are designed to fit together and fill the surface without gaps or overlaps. He designed Metamorphose III, a 42 foot mural for the post office in Kerkplein, The Hague in 1967-1968. A portion of this mural is shown in the stamp below with a picture of Escher in the lower right hand corner.

    He designed several postage stamps for the Netherlands. I believe the ones below (1949) are the only ones which were issued.

     A number of Escher's tilings have been used by crystallographers to illustrate the various ways in which the lattices in crystals arrange themselves.

     Escher became interested in "impossible" objects, those that are impossible in three dimensions, but can be created in two dimensions to make an illusion in three dimensions. The cube displayed on the stamp below is used in both Man with Cuboid and Belvedere, from 1958. In Belvedere the structure also is based on the impossible cube. Waterfall, 1961, also explores the cube.