A method for constructing peptide-nanotube-based films is demonstrated. A centimeter-sized film of diphenylalanine is successfully formed. The formation process includes the dissociation of nanotubes in a polar cosolvent solution and their recrystallization in spherulitic form on solid substrates, while preserving the basic crystallographic structure of the nanotubes (see figure and cover). In addition, silver-embedded peptide nanotube composite networks are created.