The reason only God can make a tree – according to Woody Allen – is that it is so hard to figure out how to get the bark to stick to the trunk. One of the few humans who have tried is the Italian artist Giuseppe Penone, but there are also more conventional ways of protecting trees with what could be seen as artificial bark: Kulturholz covering Naturholz. Alvar Aalto echoed this technique by adding ceramic tiles to concrete pilotis in his attempt to recreate some of the qualities of Finnish forest space. In addition to such visual references to trees, Aalto experimented with actual wood in all of its forms and contemplated the specific qualities of the material. He emphasized the naturalness of wood and the direct transportation of its material qualities to traditional architectural solutions.