What kind of treatment is the 'bio-processing' mentioned in the description?

Single jersey is the most basic knit structure knitted by looping a single strand of yarn. The front has a fine vertical grain while the inside has a different grain, so while it is thin and light, the edges tend to curl up. Bio-processing refers to a finish that uses enzymes on this to break down and shave off the fuzz raised on the surface of the cotton. Once the surface is cleaned up, it pills less and feels much smoother to the touch. This T-shirt is made of 100% cotton, single jersey finished in that way^[2][3].

The care instructions are quite cautious for a garment knitted from just cotton. Laundering is specified as dry clean alone, and for detergent, a liquid neutral detergent should be used while avoiding those containing bleach or fluorescent agents^[4][5]. Do not use a machine dryer either^[6].

The brand has not disclosed why it is restricted this way. However, in general, thin cotton knit fabrics are prone to shrinking or twisting their grain when exposed to water and heat, and dyed colors may bleed during the first wash and transfer to other clothes. Because the heat and tumble of a dryer particularly increase that shrinkage, it is safer for such garments to have water pressed out with a towel and then be laid flat to dry after shaping. Bleach and optical brighteners are usually avoided because they can fade the color or alter the original shade.

hmmm, for a garment whose touch has been refined even before wearing, these care instructions read close to the conditions for holding onto that initial state just as it was.