This thread sums it up nicely.
http://www.quiltingboard.com/main-f1...s-t181902.html

This one has more detail.
http://www.quiltingboard.com/main-f1...l-t127678.html

I just prewashed a bright red print in both! I prewashed on hot with Retayne, then washed in warm with Synthrapol as insurance against fading and running. Hope it works.

I never knew about these products. I just bought some quilters cotton solid black at Joann's. I usually use Kona, but was a little short this paycheck, and had a 50% off coupon that I couldn't use on Kona black. I will get some reTayne and wash it before cutting. So glad I saw this thread.

I purchased Retayne from JoAnne's on-line when it was on sale. Will be using it on a bunch of red fabric I was afraid to use before washing. :thumbup:

Maybe it's just the home schooling mom in me, but a great way to remember this is Retayne before sewing, Synthropol after, just like the letter 'R' comes before 'S' in the alphabet. LOL, this is how I remember things, and help my girls retain things in school.

Whoops, didn't realize someone else had already had that thought. Great minds think alike!

I always keep some of both of these products on hand!

Thanks! Now I will always remember when to use each. I bought my Retayne at a LQS.