Things You'll Need
Large plastic tablecloth
1 packet of soda ash
String or rubber bands
Large resealable bag
Tie-dyeing is as simple as wrapping a string or rubber band around an article of clothing and dipping it in dye. It is so simple that children of various ages create tie-dye items for school or home. Instead of the traditional tie-dyed T-shirt, consider tie-dyeing sweatpants. Most sweatpants are made of a heavy cotton fabric that is ideal for tie-dyeing. Key to dyeing sweatpants is the preparation needed for the dye to adhere to the fibers.
Spread a large plastic tablecloth on a flat surface such as a driveway or countertop. This will protect the area from any spilled dye. Put on the rubber gloves.
Open the packet of soda ash and add it to a large bowl. Fill the bowl with water and agitate to mix the water and soda ash. Saturate the pants completely in the mixture for 20 minutes. The soda ash water will help the dye adhere to the fibers of the cotton sweatpants. Most tie-dyes come with soda ash, but it can also be purchased at craft stores.
Mix the dye in a large bowl according to the instructions included within the kit. The dye will be added to hot water as stated in the instructions. If the instructions do not include 1 cup of salt, then add this to the dye mixture also. Salt helps the dye set to the fabric. Agitate the mixture completely with a long spoon. Repeat the process, using a separate bowl for each dye color.
Remove the sweatpants from the soda ash water and wring out. Tie the sweatpants with string or large rubber bands. The tighter the string or bands, the more likely the dye will not soak underneath the area. Discard the soda ash water.
Hold the sweatpants in one hand and dip one edge or corner into the first bowl of dye. Hold the pants for a count of 30 seconds and then retract it. Repeat the process with another dye color. While you can dip the sweatpants entirely into the dye solution, the colors may not blend. Experiment with the coloring of the pants until you are satisfied.
Transfer the sweatpants directly into a large resealable bag. Allow the pants to sit overnight to let the dye thoroughly absorb into the fibers. Remove the sweatpants in the morning, snip the string or bands and rinse with cool water. Put the sweatpants into a washing machine and wash alone through a normal cycle with cold water. Hang to dry.
Always wear protective clothing when tie-dyeing to prevent stains.
The sweatpants may drip dye when removed from the resealable bag.
Do not wash the sweatpants with any other items of clothing for the first two washes as the dye may transfer.