I've been quilting for nearly 40 years. I don't pre wash -- I use color catchers when I wash the quilt before gifting it. Have never had a problem with using the color catchers. Before those, I was a bit more selective with fabrics purchased and threw something white (like one of DH's old tshirts) in washer with it. Never had a problem then, either. I iron with steam but I don't pull the fabric, it works fine. There are many different ways to do things right!