Troubleshooting Strange Fading Patterns and Discoloration

Q: Some of my indigo-dyed pieces have developed yellowish haloes around what used to be light blue (dry already for weeks) and one developed a random yellowish streak where I would guess it had been exposed to direct sunlight? Any idea why this is happening or what I can do to get better results next time?

A: This type of fading/discoloring sounds to me like classic not-properly-scoured results. To properly scour your fabric prior to dyeing boil it in soda ash for at least 4 hours, then rinse thoroughly. Cotton (and other natural cellulose fibers) are often sheathed in waxes and pectins which are not ideal bonding sites for indigo because they can (and eventually will) separate from the cellulose fibers themselves, taking any indigo attached to them. Properly scoured fabric is free of these compounds and you’ll find that those fabrics dye more easily, evenly and the colors hold up best.

Also, did you properly wash and pH balance your pieces after removing them from the dye vat? If you leave them as is (without an acidic rinse) they have a tendency to fade as you’ve described when exposed to sun and humidity. If you are using my dye kit, be sure to use the provided Citric Acid as described in the instructions. If not, adding a half cup of vinegar to all the pieces in a load of laundry is strong enough to get them pH balanced.