I was taught to prewash and so I did. Along came precuts and that didn't make sense to me to prewash them so I didn't. Then I decided, I'm not going to prewash at all! I have made at least 50 quilts probably more, numerous table runners, lap quilts, placemats etc. I have not had any issues at all. Once I am finished, I wash the quilt in warm water, perm press cycle and throw it in the dryer. I love the crinkly look the dryer gives it. Reading prior posts, it makes sense there had to have been some shrinkage but it didn't affect the quilt much. Since I did not measure before or after, I honestly can't say how much shrinkage there was. I really love the look and feel of the quilt straight from the dryer, and so I'm sure I 'll continue on with not prewashing. Except for garments - that fabric will get prewashed!