http://www.prochemicalanddye.com/store/home.php?cat=323
Read about Retayne and Synthapol. It is somewhat confusing.
Retayne
Use Retayne before you cut and piece your quilt or garment.
Color fixative for commercially dyed cotton, linen, and rayon fabric that bleeds.
Use it in your washing machine or by hand washing with hot water.
Test fabric before washing it for the first time.
Only one application is necessary.
When to use Retayne
Test your fabric before treating it with Retayne.
Dampen a small square of 100% cotton white muslin.
Place it on top of the colored fabric to be tested.
Iron the fabrics with a hot iron until dry.
Inspect the muslin and if there is any transfer of color, then treat your fabric with Retayne.
Synthrapol
Will remove excess dye from hand dyed fabrics.
Will remove sizing from fabric before dyeing.
Use in the dye bath for even color.
A concentrated wetting agent, known as a surfactant.
When to use Synthrapol
To wash hand dyed fabrics before using them in a garment or quilt.
When fabric is already quilted and bleeds into adjacent fabric.
To soak fabric before dyeing.