Only trees from sustainable German forests are used for RA 1.15’s corpus. The beech trees are harvested at the age of about 120 years. The trees used in RA 1.15 were likely young shoots at the time of the discovery of X-rays by the physicist W.C. Roentgen and the publication of the book The Time Machine by H.G. Wells in 1895. The inner layer of the chair body is made of beech wood and the top layer of walnut veneer. Other top veneer layers and a wide range of colors are available on request.