To lighten fabric, you will have to use bleach or another commercial lightener such as Synthrapol. Sunlight also has a bleaching effect but the amount of lightening will be determined by the degree of colour in the fabric. Both bleach and Synthrapol are chemicals that should be used in a well-ventilated area. There are several steps you can take that will help you lighten your fabric without causing damage to the material. The quality of the fabric will impact how successful you will be at discharging the colour. Synthetic fabrics may be more difficult to lighten than natural fabrics.
Set your workspace up outdoors or in a well-ventilated area. In order to protect your table or surface, cover with a large garbage bag. Place two buckets on the surface or close by. One bucket will contain the bleach solution and the other water. Rubber gloves should be worn to protect your skin.
Prepare your mixture of bleach and water. The bleach must be diluted to avoid causing the fabric to deteriorate. Pour 1 part bleach to 4 parts water into the bucket. Fill the other bucket with cold water and set to the side.
Place the fabric in the bucket containing the water and bleach mixture. Stay close because the colour may fade fast. Leave fabric in the bleach and water mixture for 10 minutes and check colour. The fabric should remain in the bleach and water mixture until the colour fades to the colour you like. You may need to leave the fabric in longer if your fabric is dark.
Remove the fabric from the bleach and water mixture. The fabric should be rinsed immediately in the bucket of cold water. Make sure all the fabric is rinsed or colour may fade unevenly.
Remove the fabric from the bucket of cold water. Place the fabric in the washing machine and wash for a full cycle in cold water. Hang the fabric on a clothes line or dry per the fabric instructions.
If soaking in bleach will ruin fabric, you can try soaking the fabric in vinegar and water or a mixture of baking soda and water.
The results of lightening fabric with bleach can yield unpredictable results.