Peptide nanotube-based spherulitic films are a recently discovered phenomenon, which was demonstrated in the case of the self-assembled diphenylalanine peptide nanotubes. Here we show that the film-formation method can be implemented with other peptides. We also demonstrate that a critical physical parameter, an elevated level of environmental hydration, is required for film growth. A possible formation mechanism is suggested. The optical, morphological and mechanical properties of these films are characterized and are found to be substantially different from those of non-spherulitic deposits. (c) 2009 Elsevier Inc. All rights reserved.