Lisa, perhaps a "gentler" way to fix the dye would be to order a dye fixative from one of the dye companies (I got a huge jug from Pro-Chem (they of the catchy 800 # = 800/2BUY-DYE)) they market it under the name Re-tayne.
It is suppose to both fix any unfixed dye and wash it away so it will no longer cause bleeding problems. I've used the entire jug, using 1 tsp to the yd. when prewashing all my new fabrics - it seems to work well (no bleeding to date - and I have a rather awesome fabric collection!) The gallon was around $14 if I recall, well worth it from my perspective. I've also heard about the vinegar bath, but have heard that it's a fairly caustic way to treat your fabric.
I use 1 part vinegar to three parts water whenever I have a problem with fabric bleeding. it does not hurt the fabric so far as I can tell. But I am always careful to rinse out the vinegar very thoroughly so that it doesn't eat into the fabric for years.
If vinegar in the water doesn't stop the bleeding I decide whether or not to keep the fabric. If I do keep it, I put it in a special pile with a note folded into it (not pinned) reminding me that it continued to bleed. I keep these fabrics in a special place. But of over 2000 fabrics I have only found three that continued to bleed after the vinegar treatment. If I decide to use them, it will be with dark fabrics that wouldn't be much affected.
If the suggestion your quilt shop owner suggested doesn't work, what you need to to is buy some SYNTHROPOL (a detergent used by dyers to remove bleeding dye from fabric). You put a teaspoon of the stuff in hot water and wash the bleeding fabric, rinse and wash again if needed. Once the rinse water runs clear your fabric is dyefast.
I am an experienced dyer and swear by the stuff! You can order it from places like Pro Chemical &Dye Co. Very inexpensive. Call 800/2BUY-DYE to order. If you have a yarn shop that sells dyes for fibers, they will likely stock Synthropol because you really need it for any kind of dyeing, wool or fabric.
Boy am I confused! Based on the comments on this topic I called 800-2bye-dye number to order some Synthrapol. They directed me to their non-800 number saying they didn't think this was the product I wanted. The customer service people told me synthrapol is a fabric wetting agent used to prepare fabric for dyeing, but does not work to set dye. They recommended retayne for this purpose.
Does anyone know what gives? Judi
Retayne actually SETS errant dyes so they'll stop bleeding, the 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. I used my entire gallon of retayne as a "prewash" for my new fabrics, Now that it's gone, I'm using the synthropal for the same purpose.
Just from my own "bleeding thread" experience, I'd say try it first with the Synthropal - you don't wnat to "fix" the dye that's already moved to the wrong areas of the quilt, you want to "float" it away. Mary Beth
Synthrapol is a "super surfactant" meaning it scours fibers of sizing, oils and other stuff that might interfere with dyeing. You use it to prewash fabric prior to dyeing.
Its other function is to remove UNREACTED dye from fiber after you finish dyeing something. So dyers wash freshly dyed material in it to get rid of unreacted dye--which is the cause of most bleeds.
Synthrapol DOES NOT work to set dyes. The soda ash or salt that you add to the dyebath has that function. What it does do is get rid of excess dye that will, if not removed, bleed the next time the fabric is wetted.
So the Pro people were right -- it doesn't set dyes. But you still need it if you want to use it to prewash quilt fabric to remove any unreacted dye before you put the fabric in a quilt.
It would be heaven if all fabric manufacturers used something like Synthrapol to remove the bleeds. But they don't. And some intentionally leave the excess dye in the fabric to make it appear darker when you buy it. So that's why prewashing with Synthrapol is a good idea for suspicious fabrics or even those that you can see will bleed a little. Judy