The question of pre-treating fabrics has always made for great debates.  Personally, I don't like the kind of potential surpise distorted quilts or running colors can bring so I pre treat my fabrics.

I have been told you should pretreat fabrics in the same manner the fabrics will be maintained.  For me that means machine washing with detergent in the appropriate water temperature and drying in the dryer at the appropriate setting. A word or two of caution tho, be sure all detergents are rinsed out thoroughly to avoid a cloudy appearance and a funky feel and also beware of dryer sheets as not good for all fabrics!

Another approach is to put your fabrics in the sink and agitate by hand.  I have used this method when I have a very small amount of fabric to treat or highly suspect colors.  I know of some sewers that use HOT water.  I don't personally know about the hot water idea, but the sink method does have merit if for no other reason than to see how the colors react in the water.  Nothing worse than one bold color running all over other fabrics.

More food for thought:

•  Consider using fabric rinses especially designed to remove excess dyes.
•  Use good old fashioned vinegar to set colors.
•  Read the end of the fabric bolt for fabric care information.
• Reduce fraying by clipping corners!
• Reduce wrinkles by removing fabric from dryer promptly if not ironing right away ~ if ironing immediately, don't let the fabric dry completely!

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