I never prewash and have never had any problems. I just washed a quilt that had some really dark, (almost black) purple batiks, and whites. I threw in a couple of color catchers, and had absolutely no problems. If I had to prewash fabric, I would give up quilting.

I don't prewash anymore because I buy some precuts like jelly rolls and layer cakes and those can't really be prewashed easily. I will sometimes wash though. For example I bought some yardage and then noticed the lady who cut it eating. My dd has severe food allergies so in order to reduce the risk of her having a reaction to the fabric somehow I will wash it.

I saw on a post earlier when i asked the same question. to use horse shampoo, it doesn't hurt the fabric in anyway.

I think that was "orvus" or something.

I just wash all my fabric with my reg. laundry det. I'm not sure if this is what you are talking about.

You can use Retayne to prewash your fabric in - Retayne actually SETS errant dyes so they'll stop bleeding.

Synthropal "floats" out any unfixed dye and keeps it from "fixing" itself onto areas of the fabric that you don't want to be stained.

You can also use color catchers by Shout when washing the material.

Like Sewcrafty, I just throw my fabrics in with the regular laundry when I buy them. If thee are a lot of darks, I'll add a color catcher or dye grabber. I don't iron until I go to use them, but if you take them out of the dryer right away,they are generally not too wrinkled. I even do that for stack and whacks and haven't had any problems with aligning the layers.

I'm a prewasher as well. Probably comes from my garment sewing days. But it's also what I was told when I first started quilting. I use my regular laundry detergent - happens to be Arm & Hammer powder, in warm water and sort by relavent colors same as I do my normal laundry. I do not wash it with my laundry as I use softener for my clothing but not my fabric. Prewashing removes all sizing, chemicals, etc. and hopefully you discover any drastic fading/shrinkage in the process. I then dry in my dryer. Interestingly enough, I took a serger class from a LQS a few months ago and the instructor (also a quilter) mentioned that unless you are drying your fabric with a FULL LOAD of laundry you don't necessarily get the full shrink rate as it does not take as long to dry even a couple of yards of fabric as it does a full load of clothing. I haven't bothered with that but it does make sense to me. I then wash with detergent and softener when the quilt is completed. Getting the 'crinkly' look that I love with the batting shrinkage.

Because my fabric is of unknown parentage generally, I prewash everything except fat quarters and a jelly roll I just bought. I use regular detergent and heat in the dryer, I do try to iron as it comes out of the dryer, tho. I figure I don't need special soap, tho if I had a really special antique quilt I might indulge it.

I don't usually pre wash most fabric. Intense colors I do. This week it was a good thing I prewashed some black fabric, it was a real bleeder. After I saw how dark the color catchers were I put it in the sink and washed it several more times and it was still bleeding. I didn't have anything in the house to set the dye and it would be 100 miles round trip to go buy some. I put the fabric in a large pan and boiled it, rinsed then took a very small piece of white fabric , put it inside a wad of wet black fabric to see if it was still bleeding. After about a half hour the white was still white and I can use the black fabric. Glad I took the time to pre wash this time.

I do not prewash unless I bought it from a yard sale or thrift shop. I love the look of a quilt after it shrinks in the wash. It kind of gives it that old time look. I always use a color catcher so that the colors don't bleed on to each other. It's just personal preference.