The iron frame is made of grey cast iron which is cast by modern production methods that protect both the employees and the environment. It reduces emissions and guarantees a nearly perfect surface. 


Formerly the key surfaces were made of ivory. However as using ivory contributes to the exploitation of animals a special plastic material was developed which, after polishing, has a warm and smooth feel to touch. 

Wood and glue

To prevent the wood from warping and to give it its optimum strength solid timber is cut into layers and glued together. 


In the application of environmental friendly polyester and paint GROTRIAN leads the way. To ensure the good health of all employees and an environment friendly work process the spray room recently has been equipped with a cutting-edge airflow system, that filters all spray mist and absorbs it in a water circle. A special bond extracts the damaging particles and cleans the water.