I wash everything. I am a new quilter, but I have been sewing for over 20 years. I have always washed as purchased so that everything is ready to use when I want it. I wash precut fabrics in a big bowl with a little detergent. I let them soak and then rinse well and wring out. I then dry them in the dryer and I have never had a problem with them coming apart. I would much rather have the fabric shrink before I use it to make something.