The Castellum Theater is clad in customized corrugated aluminum panels. The corrugations are small and form a wave-like pattern, referencing the nearby river. The panels are manufactured using explosive forming. Explosive forming uses the force of an explosive charge in a medium (often water) to form a metal sheet against a mold. This process has relatively low capital costs and is good for small to mid-volume production runs. It has very high tolerances and can produce large curved panels (similar to car hoods) or small details such as those on the Castellum Theater.