Casein is a kind of biomolecular condensate that is produced by mammary cells and found in milk as colloidal casein micelles. When eaten as food, casein supplies amino acids, carbohydrates, and the essential minerals calcium and phosphorus , which is widely employed in the textile sector for a number of applications such : Printing ,Finishing, Sizing , Adhesive ,Dyeing and Casein Fiber. in This chapter provides a brief and comprehensive overview of the casein's manufacturing and applications in textile as well as finishing processing such Antimicrobial ,Flame-retardant , The durability, physiological comfort and UV protection. Casein is a flexible protein kind of biomolecular condensate that is produced by mammary cells contains a high concentration of proline amino acids, which inhibit proteins from generating secondary structural motifs. All things considered, casein is a substance with a wide range of uses in the textile sector .