We frequently get asked "Should I pre-wash my fabric?" So, I thought I'd share some information I recently received from P&B Textiles.
"Care and treatment for your P&B Fabrics:
It is the nature of cotton fabric that some changes may occur when it is washed and dried. Regional water quality, water temperature, detergent varietes and dryer temperture can all affect shrinkage, bleeding and fading.
At P&B Textiles, we pride ourselves on producing superior fabrics, which will retain their quality if properly treated. Please help to educate your customers about the proper care of cotton fabrics:
* If you are making an art quilt or wall hanging that won't be washed, it is recommended that you do not pre-wash your fabric.
* If the quilt is dusty, tumble it in a cool dryer for a few minutes and shake it out.
* If you pre-wash fabric, do not use hot water or a hot dryer. Once quilts are made, they should only be washed and dried in cold water and a cool dryer (or dried flat) and only if the fabric was pre-shrunk prior to construction of the quilt.
* If you are making a quilt with light and dark fabrics, it is suggested that you pre-wash dark fabrics to remove any potential bleeding. This can be done in cold water. A good test of bleeding is to add a light colored or white piece of fabric to the dark wash, and see if any color bleeds onto it. If so, repeat the washing process until the light-colored swatch comes out without any color change.
* Detergents can fade fabrics. It is recommended that you use a gentle detergent to wash quilts, and no detergent at all for pre-shrinking. Orvis is recommended.
If you have followed these guidelines, your fabric should not shrink more than 5% selvage to selvage, and most fabrics won't bleed or fade at all."
Even though these guidelines are from P&B Textiles, I have received similar recommendations from other manufacturers. Hope this helps when you're trying to decide whether to pre-wash or not to pre-wash.