Originally Posted by ckcowl
vinegar setting the color is a (false) old wives tale.
only acid dyes are set with vinegar-
acid dyes are not used on cottons.
the addition of vinegar may freshen the water- but it is an unnecessary expense.
Originally Posted by suesembroidery
I put it in the washer and soak it with reg soap powder, than put it on spin. Fill up the washer with 1 cup of vinegar and let it soak again, than spin. Vinegar sets the color and delutes the suds and doesn't put wear and tear on the quilt. Watch your water color and you will know if it is clean. Soak time is about 30minutes or if I am busy it is when I remember. Never had a problem. 10-20 minutes in the dryer and layed out after to dry.
You are correct about vinegar not affecting the dye, but it can help rinse out the soap residue. The acid dissolves the soap, releasing it from the fibers. It's especially helpful if you have hard water.
But no, it's not necessary. If you want to use it, do so. If you don't, it won't hurt anything. :)