Casein glue is a type of adhesive made from casein, a protein found in milk. It is created by extracting casein from milk and then mixing it with water and other ingredients to form a sticky substance. This glue is known for its strong bonding properties and is often used in woodworking and crafts. One of the key benefits of casein glue is its natural origin, making it an eco-friendly option compared to synthetic adhesives. It dries clear and can be sanded or painted over, making it suitable for various applications, including bookbinding and paper crafts.