Answer:
Due to lack of bonds.
Step-by-step explanation:
The indigo dye did not adhere to the different fibers because the indigo dye did not make bonds with the fiber, it only attached to it physically for temporary period of time. The reduced state is also necessary for indigo because indigo cannot dissolve in water, but when it is reduced it can soluble and able to get inside a fiber to make physical bond with the fiber. Some interactions are stronger than others because of the presence of strong bond between the two different materials so strong bonding makes the materials to attach with each other for a long period of time or permanently.