Silk protein coatings

A method of coating hair or skin with a silk polypeptide, the method comprising the steps of:

• i) providing an aqueous solution of the silk polypeptide, and
• ii) applying the solution on the hair or skin, thereby coating the hair or skin with the silk polypeptide and improving hydrophilicity of the hair or skin,
• wherein
• the silk polypeptide consists of (C)m, (C)mNRz, NRz(C)m, or NRz(C)mNRz;
• or the silk polypeptide consists of (C)m, (C)mNRz, NRz(C)m, or NRz(C)mNRz linked to an artificial tag, wherein the tag is a lipid, a dye, a conjugated metal, an activated carbon, or a tag to facilitate purification of the silk polypeptide, wherein
• C is a repetitive unit having an amino acid sequence of SEQ ID NO:
• 21,
• m is an integer from 2 to 80,
• NR is a non-repetitive (NR) unit NR3 having the amino acid sequence of SEQ ID NO:
• 41 or NR4 having the amino acid sequence of SEQ ID NO:
• 42, and
• z is an integer from 1 to 3.