Milk Protein Top Fiber

after research I found that:

Milk fibers are regenerated protein fibers made from casein, which is derived from milk after the butterfat is removed. Milk fibers are made using the viscose process. 

Because this is a protein fiber, it dyes as easily as wool.

Milk protein fibers were invented in the 1930s in both Italy and America. It was used as a substitute for wool in clothing and household goods during the 30s and 40s because wool was needed by men on the front lines. After WWII, it fell in popularity as newer, cheaper alternatives like nylon grew popular.

-absorbs moisture well
-antibacterial and antifungal, and contains amino acids
-glossy and luxurious in appearance and feel and as comfortable as silk
-easy to dye
-blends well with other fibers.