Originally Posted by
KerryK
I'd love to know where you buy Synthrapol. I googled it, and it brought up several different kinds. So, I need to know which kind to get, also. I am about half way finished with a batik quilt that was not prewashed, so it will definitely need to be washed. I also like the idea of taking it to a laundromat to wash and dry. It is a queen size, so I don't think it would wash well in my regular washer.
Synthrapol is Synthrapol -- I don't think there are different kinds, just different ways of describing it. Usually quilt shops that cater to dyers carry it. Otherwise it is widely available online from places like Amazon, Dharma Trading, ProChem, etc. Here is a link to it on Amazon:
http://www.amazon.com/Craft-Synthrap...dp/B000YZ3UHQ/
Synthrapol requires *hot* water to work properly. I tend to use the largest front-loading washer at the laundromat so that there is plenty of water for the dye particles to disperse into. What Synthrapol does is suspend in the water any loose dye particles (dye particles that have not permanently bonded with the fiber).
There are two reasons why fabrics bleed.
One is when the manufacturer over-saturates the fabric with dye -- more than the fibers can absorb -- and does not rinse sufficiently to get all the loose dye particles out. This type of fabric, when prewashed, will stop bleeding after one or two washings.
The other reason is when the manufacturer failed to correctly set the dye. In this case the fabric will continue to bleed through many washings. This is when you can use Retayne at home to try to permanently set the dye. Some fabrics require two treatments with Retayne to stop bleeding. Any fabric that still bleeds after two treatments with Retayne should not be used for quilting. Also, once Retayne is used the finished quilt needs to be always washed in cold water as the Retayne treatment can be lost in hot water washes.
It's pretty easy to test fabrics. Cut a small piece (maybe 2 inches square) and place in a plastic cup of water. Leave for a couple of hours. If you see dye bleeding into the water, you may want to prewash. If there is no dye in the water, rub the damp fabric against a white fabric (or other fabrics in the quilt) to see if any dye transfers that way. Unless the fabric is an obvious bleeder, I do not bother to prewash *but* I do use Synthrapol in hot water in the largest front-loader at the laundromat for the first washing of a quilt.