➀ Researchers from Politecnico di Milano and collaborating institutions developed hydrophobic paper using the mechanical properties and water resistance of cellulose nanofibers. The study aims to create a sustainable, high-performance material for packaging and biomedical applications. ➁ The approach combines short protein chains (peptides) with cellulose nanofibers without chemical modification, enhancing their mechanical performance and water resistance. ➂ Incorporating fluorine atoms into the peptides creates a structured hydrophobic film, improving water resistance while maintaining biocompatibility and sustainability.