There have been many posts about the pre-washing fabrics with opinions both for and against. Some say pre-wash everything, others say don't bother, and still others say that you only have to worry about colors bleeding in less expensive fabrics and in batiks.
Today I tested 2 LQS pieces of predominately black fabrics from Moda before using them. You can see the result in the picture. After seeing the sink full of black water, I immediately used Retayne with good results. After the 20 minute treatment, I rinsed the fabric, and the water ran clear.
This is my "show and tell" for the day.