Blue Blue Japan uses all natural indigo dyes in the making of their products. Indigo dying is an ancient process, and requires special care. To get the distinctive blue hues, fabrics must be dyed over and over to get increasingly dark tones, sometimes up top 20 times.

So how do you take care of your indigo? The helpful folks at Blue Blue Japan sent us this guide:

"The traditional Japanese indigo dye is made from fermented "SUKUMO" with some scum, Japanese rice wine "SAKE", wheat brans and so. "SUKUMO" is made of "Tade (Persicaria tinctoria)" plant leaves grown originated in Japan. PURE (natural) indigo dye is used to mean this "SUKUMO" using indigo dye."

"The PURE indigo dye is able to create original deep indigo blue color by repeating the process of dipping in the dye liquid, oxidizing with fresh air, rinsing in water and sun drying. Usually repeat 4 to 5 times to create deep indigo blue. PURE indigo is able to create beautiful deep indigo blue. Light indigo color is pure and translucent blue and dark indigo color is reddish deep indigo blue. After repeating of washing, the scum component will be off from the dyed material and indigo color becomes brighter and sobered blue."

"The PURE indigo dye has more color stability compared to the synthetic indigo dye. After many times of washing, color transfer will be reduced. Be aware of color transfer to others by friction and wetting when wearing and carrying of the PURE indigo dyed product. Wash separately with mild detergent. Do not use bleach. Keep PURE indigo dyed product in dark place and keep out from sun light and light especially fluorescent light to avoid color fading."