Originally Posted by YaYaBean
The color is also distributed in squares across the front of the quilt. Would you still take the quilt apart and treat the back separately from the front of the quilt?
Honestly, I'd be tempted to finish the quilt and then take it to a laundromat, find the biggest front-loading washing machine possible, and wash it several times in Synthrapol.
The biggest risk is from the single large piece of backing fabric. If taking the quilt apart, that is the piece I would work on using Retayne and subsequent testing.
The smaller pieces on the front might still crock, but probably not in significant amounts. It would be enough to make sure that the quilt does not lie on itself while damp. Take it out of the washing machine immediately after it finishes; don't let it lie there for awhile. And again, wash several times with Synthrapol to at least get the worst of the crocking dye out of the fabric.