This is an a topic of ongoing debate, but I can't understand why? I know the fabric right off the bolt is so perfect looking, and very tempting to begin cutting. It's pressed so flat with no frayed ends. So hard to resist beginning your project. But I always do. Straight home from a quilt show weekend, where I usually stock up, my newly purchased yardage goes directly to the laundry room to be washed, dried and ironed, and I encourage all my students to do the same.
Why wash? For two very important reasons. Fabric production is not standardized. Therefore manufacturers produce fabrics with a variety of weave counts. Some may have a count of, for example, 55 x 65 and another may have a count of 70 x 77. When you sew them together via, piecing, applique or whole cloth quilting and then you wash the completed project the fabric will shrink at different rates cause distortion. This reminds me to let you know to never use bed sheets. They are too densely woven to comfortably needle through for hand quilting. Also, you want to dry your fabrics in a nice warm dryer to get all the shrinkage out and iron.
The second reason for washing, especially the hand dyed fabrics is to reduce the amount of potential or actual bleeding. I use many hand dyed because they are so beautiful, but I wash them, several times in a wash tub of hot water and Retayne, a commercial color fixative. You can see that item on my store under, Quilting Accessories. This is especially true of reds and all darks.
