It is important to let a newly tie-dyed shirt soak for at least one hour before washing it. It is even better to let it sit for a 24-hour period. Keep it in a warm and moist place, such as a plastic bag.
Open the bag and remove the rubber bands
Gently unwrap the wet tie-dye creation in a place that can be cleaned if necessary, such as a kitchen sink. Excess dye is likely to drip off, so take precautions. Remove the rubber bands used to tie the design and discard them.
Rinse with cold water
Open the shirt and give it a good rinse in cold water. Gradually increase the heat until the water is hot. Keep rinsing until the water runs mostly clear.
Wash in a washing machine
Cleaning the tie-dye shirt in a washing machine removes all the unabsorbed dye. Do not add it to a normal load of laundry, as it is still leaking dye and may stain the other clothes. Use soap as normal and finish by drying with the regular laundry.