Fish scales are calcium phosphate composites coated with a mucus layer. Fish scale properties have been mimicked by polyacrylamide hydrogels, which are both hydrophilic and mimic the mucus’ retention of water. Additionally, fish scales have been used as a template for a casting technique, and as a model for a lithography and chemical etching techniques on silicon wafers that exhibited oleophobic contact angles of oil in water of 163° and 175°, respectively.