From 1927 onwards, Gerrit Rietveld's experiments were centred on designing chairs made from one piece of material. This idea fascinated Rietveld for many years to come. One of his earliest, more creative designs includes the Birza Chair. This work was Rietveld's first one-piece design ever realized. It was made for the Birza family in Amsterdam. It is constructed out of fibreboard, originally known as Vulkanfiber. Because it was so difficult to build, only one chair was made. Rietveld's assistant, Gerard van de Groenekan, refused to replicate them. Furthermore, Rietveld was unable to convince anyone to commercially manufacture the model.