Walnut. The number of pieces comprising each scenario varies notoriously. The Presentation was fashioned from a single block of wood that was reinforced by several braces attached to the hollowed-out rear. The Adoration of the Magi is a group of several differently-sized figures that have been nailed and glued together. The Birth is made up of two main pieces of wood whose joints were additionally reinforced with braces and a large number of nails. The marks of different woodworking tools and saws may be observed where the pieces were adjusted to fit into the main altarpiece frame and to join different contiguous pieces of wood together.