1973 Crane with 'spielgut' quality mark
Spielgut, founded in 1954 is an independent German organization that assigns to toys that meet strict requirements. Professionals from various disciplines such as medicine, psychology, education, art and architecture approve the toys on a number of criteria which include design, materials, colours, pedagogical principles and safety.
During the years the spielgut quality mark has been awarded to many designs made by Rokus and Corry.