Siem (Simon) van der Marel (1944 — ) is a Dutch glass artist and since 1966 designer for Glass Factory Leerdam. His creations excel in quality, simplicity and clarity.
Leerdam N.V. Glasfabriek. Founded in Leerdam in 1878. Under the direction of P.M. Cochius the factory began to modernize business operations, laying the foundations for the craft industry. K.P.C. The Basel was the first artist to design a range of glassware for him. In 1929, Andries Copier received the artistic leadership of the glass factory. After the Basel, there were still more external designers; Cornelis de Lorm, Chris Lanooy, H.P. Berlage and Chris Lebeau. After 1930, the production of use glass and Unica glassware was handed to Copier, Floris Meydam, Willem Heesen and Sybren Valkema.