Recently, I received this email from a customer
I bought a prom dress from you in 2010, and I loved the way it looked and felt on me. It is 100% polyester, floor length, and beaded with a cinch at the waste. I am now getting ready to get married and really want to re-purpose my dress. I am looking to take it to a tailor to get it fitted, but I am in debt due to student loans, so I am looking for as many DIY projects as I can do. I am interested in bleaching it if that is possible without damaging the dress. I would really appreciate any kind of advice you can share with me. Like I said, I LOVE this dress and it would mean so much to me to be able to wear it on my wedding day.
Bleaching fabric is difficult and under the best conditions may not turn out the way you hope. Bleach can ruin polyester, leaving it stiff and yellowed (the fabric may lighten, but the result is no where near white).
The best option to change the color of polyester fabric (or any synthetic) is fabric spray. Rather than bleach, use a white fabric spray, it is a spray paint specifically designed for fabric. The pump sprays (like the Tulip brand) tend to clog within minutes, so I prefer Simply Spray. Amazon tends to have the best price here.
First try the spray on fabric from a matching wrap or extra fabric left-over from a hem. Practice the spray pattern and coverage before using on the dress.