My son is getting married in September, and my best friend, so incredibly loving and generous, has offered to give them a gorgeous queen sized quilt she made from batiks. Unfortunately, she has told me she never bothers to prewash her fabrics. Looks like I will be presenting the happy couple with some Retayne or color catcher sheets and the advice to use them once it needs laundering. My question is: previous posts have advised 1 tsp Retayne per yard of fabric for pretreating. How much would be used for a queen sized quilt made with a thin all cotton batting?