For simpler, less articulated pieces, like large-scale representations of organs, he used plaster molds lined with several layers of colored paper imbibed with glue. The glue-moistened paper follows every detail of the mold ; the layers, starting with thin paper then progressing on heavier paper, will give resistance to the future piece. The use of papers of different colours helps keeping trace of the layers. As many as twelve layers of paper could be used. The model thus obtained was hollow, light and resistant.