Biocalf comes from calfskin. Chrome-tanned, it is nonetheless a delicate leather which is vulnerable to scratches and requires special care. Being sensitive to water, it is important to waterproof your shoes regularly and take care not to use any overly abrasive resins or solvent-based products.
Clean with a dry or very slightly damp cloth. Ideally, use Heschung polish because too hard a wax or resin can alter the appearance of the grain. Apply the polish, leave for a while and then buff with a wool cloth.