How to Remove Color From Fabric
Discharge dyeing removes dye from fabric. Typically, this results in a white pattern on top of a contrasting tone or color. Most artists use one of two methods to remove dye from fabric. One requires the use of bleach, the other may require purchase of materials from specialty shops or the internet.
First: Bleach method
To discharge dye your clothes with bleach, you need adequate ventilation. If you cannot work outside in open air, open every window you have available. Put fans in the room if you have them, and position them so that they blow the bleach fumes away from your face. Wear goggles to protect your eyes. Use the bleach as you would use dye. If you need to thicken it for stamping or painting, sodium alginate works for bleach too. When you have finished dyeing, cover the fabric in plastic bags and leave it to cure overnight. After it dries, rinse the fabric with cold water until the bleach is mostly removed. Use several cold rinses followed by hot rinses to remove the rest of the bleach, otherwise the bleach may ruin your piece as you wash it out.
Second: Discharge paste method
Bleach damages natural fibers, so discharge dyeing cotton or silk with bleach increases the chance of irreparable damage later. For this reason, some dyers choose to use the discharge paste available at dye supply shops and fabric stores. Paint the paste onto your fabric, let it dry, and steam or steam iron it. Afterward, wash out the fabric with Synthrapol or detergent.