When I first began quilting, I was told to prewash the fabric before cutting. Later, the people at my LQS said that they did not. I came across some fabric that I had prewashed, and I would like to buy some complementary fabric to use with it. Should I prewash the new fabric, because the other has been washed already? If I mixed prewashed and unwashed fabrics, will it cause problems when the whole quilt is washed?

If part of the fabric is prewashed I would wash any others I used in that quilt, Normally I don't prewash my fabrics unless I think they will bleed. I like the crispness of the fabric.

I would also pre-wash the additional fabric because the other is washed. If I am using a jelly roll and mixing it with yardage (usually from the same collection), then I don't wash the yardage because I don't wash the jelly roll.

Otherwise, I do pre-wash. To get that nice crispness of new fabric I use startch.

I prewash all my fabrics for several reasons.
1. Different manufacturers fabrics will shrink different percentages.
2. Removal of chemicals, formaldehyde, sizings, cotton polish, etc. helps to fabric to be "true"
3. Prewashing gives you a view of the finished quilt.

If you do not prewash fabrics, after sending your quilt out to be quilted, after that first washing, if you have different percentages in shrinking the quilting can become totally lost in the fabrics.

The chemicals used for fabric finishing can be a health concern to several people. Some may just get some annoying "unknown" itching, rashes may appear on the skin, but more important, eye irratant.

I have been fighting an infection in my eyelids for over 2 years. I've rubbed my eyes hard enough to look like I have been hit, and my eyelashes have fallen out. Recently, an opthalmologist said it is a reaction to the chemicals in treated fabrics. Now that I prewash everything, even customer quilts, the infection is starting to clear.

I usually don't prewash, but if part of the fabric is prewashed I prewash the rest.

I agree with Up North, if the rest of the fabric that's going in the same quilt has been washed, then I wash, otherwise, I don't prewash anymore.

I usually don't pre wash my fabrics either.

I pre-wash everything but pre-cuts. Some colors run. I was glad I used Shout Color Catchers with my Downy Kid's quilt. I washed it 3 times and used a TBS of vinegar on the last.

I wash everything. I wash the dark colors after letting them sit in a vinegar soak for a while. As soon as I don't wash the darks, one will bleed. I wash all the other fabrics because I washed the darks and to get the chemicals out of them as well. To put body back into the fabric I press it using Mary Ellen's Best Press (a starch alternative). It smells so good! Everything goes to the laundry room for washing before it ever sees my sewing room. I do not, however, wash charm squares or jelly rolls, etc.

I made a dress one time for display at a fabric store I worked at and did not prewash the fabric. The dress was lovely and crisp. When I washed it after being on a display for a month, it looked like a dead towel :( I was really disappointed. The fabric was seersucker, so I couldn't even starch and iron it)