What sort of stain is it? Does it come out when you wash the fabric? Is your fabric pre-washed to begin with? If not, I wonder if it's possible that the Best Press is combining with something on the fabric and creating the stain. I am a pre-washer and haven't had this problem. If the stain does come out when you wash the fabric, I guess you could continue working with the fabric and the stain would come out when the quilt is finished and washed.