 Mèffert has also produced puzzle designs by Tony Fisher, including the "Golden Cube", and Oskar van Deventer, including the "Gear Cube".Mèffert was born in Wernigerode in the Harz Mountains of Germany on the 28 November 1939.Mèffert is the son of Otto Oscar Wilhelm Rudolph Mèffert and Emmy Johanna Frieda Von-Vorkauf.