I used to prewash my fabrics but then I thought "why am I doing this when nothing ever runs" so now I never wash them and I always wash myquilts after finishing them because I want to see any mistakes before I give them away. I have never had any problems. I put the quilt and wash it as I would anything else, but I do half dry them in the dryer and put it on the bed to finish drying. I have instructed the recipients to do it the same way and so far, after a number of years, no problems. I feel that quilts are made to be used so I make sure they are firmly sewed (I am a hand quilter by the way) and that almost guarantees it to not fall apart. Incidentaly, I "quilt" by poking the needle in and pulling it out as if I were sewing a button on. I cannot get the hang of regular quilting and after some practice, it all looks pretty good and the grandchildren are just as warm under them. I tell them that the quilt is like grandma's love and hugs and that is what keeps them warm.