I must be "charmed" so far! :roll:
I've used charm packs for a number of quilts and have never pre-washed those, (and believe me...I am a pre-washer!).
Actually getting right in and actually using a charm pack or oneof those jelly rolls was difficult because I couldn't pre-wash them easily.
That being said, I have never had a problem with shrinkage with any of them. Maybe it's because the first wash I use is on a gentle cycle. That plus I also take it out of the dryer before it's totally dry.
I'll probably have a major shrinkage problem with the next one just because I've put it in writing! :shock: