From www.greatbigstory.com — Real indigo-dyed clothing is not like the blue you know. Richer than the chemical blues used on most fabrics today, real indigo dye comes from a plant and has a surprising range of qualities: on fabric it is antibacterial, flame resistant and repels odor and dirt. With roots in Japanese culture dating back to the 1600s, indigo-dyed fabrics were worn under the armor of samurais to help keep bacteria from wounds. Today, five farmers keep the tradition of growing indigo alive in Tokushima, Japan.
Your blue jeans don’t hold a flame to Japanese indigo. The true blue dye makes clothes fire resistant, bacteria resistant, and was once worn under the armor of samurai.
Check out this great video here: https://greatbig.is/2W64vfF