How to bleach silk with hydrogen peroxide.
Recently I purchased this marbled silk crepe de chine from Mood Fabrics. When I showed it to my sister, she thought it'd look even better in a lighter hue. I liked the idea, so I set out to fade the fabric - but how do you lighten silk?
While silk is a more resilient fabric than most people give it credit for, there is a rule that you never break with silk.. do not bleach. Bleach is too caustic a substance for silk, and it can disintegrate the fiber.
But there is another way to lighten silk. Hydrogen peroxide is an excellent alternative as it's less destructive than bleach. I found a recipe online for bleaching wool and silk and followed it for this project.
What you need: soda ash, synthrapol (or other professional textile detergent), hydrogen peroxide, white vinegar, thermometer, and a large stock pot.
You can use either one cup 35% hydrogen peroxide, three and a half cups 10% hydrogen peroxide (hair bleaching strength), or six pints 3% hydrogen peroxide (first aid strength).
Note: any utensils used in this project should not be used with food afterwards.
Also, if you're bleaching a solid colored silk fabric, the results are predictable - the silk will be a lighter shade. It's a great way to bleach out stains on white silk. If you're bleaching a patterned fabric with many colors like I did, there are no guarantees to the final outcome.. all colors will be lighter, but they may not be consistently lighter as the peroxide might pull some colors more than others.
1. Fill your stockpot with water (enough for the fabric to move around freely) and bring it to a boil. Once it reaches a boil, turn off the heat and allow it to cool to 140 degrees Fahrenheit.
2. Add one half teaspoon of both synthrapol and soda ash per pound of dry fabric to the water, stir in. Add your fabric and wash it in the water. Rinse it thoroughly afterwards and dump the water.
3. Add hydrogen peroxide, one teaspoon synthrapol, and seven and a half tablespoons of soda ash to cool water (enough water to cover the fabric). Mix together. Heat bath to 130 degrees Fahrenheit, turn off heat.
4. Add fabric to peroxide bath, stir in. Submerge fabric in bath - if need be place weights such as smooth stones or glass jars filled with water on top of fabric to keep fully submerged in the water.
5. Allow fabric to bleach for 16 to 24 hours. Once it is finished, dump out and rinse in warm water thoroughly.
6. To neutralize the peroxide, you must soak the fabric in white vinegar. Add 11 tablespoons of white vinegar to each gallon of warm water and soak the fabric in it for 10 minutes.
7. Rinse well. I washed my fabric in warm water with synthrapol on delicate cycle just to make sure there was no more vinegar smell. Once it's dry, you can use the fabric!