https://smile.amazon.com/June-Tailor...rds=fray+block

I like this brand best because when it dries the fabric is still flexible and relatively soft.

I don't know if this is necessary to use on the slipper satin, but I just figure better safe than sorry

I have never actually returned fabric to Fabric.com - but on 2 occasions I got something that was wrong - whether it was me or them I don't know. They actually just gave me credit and told me to keep the fabric or donate if I didn't want it. It wasn't a lot of yardage, but I was pleased with how they handled things.

Now that Amazon bought out Fabric.com things are changing though. No real complaints yet I am just keeping my eyes open when I shop

Do test it on a scrap of the satin fabric first. I had one time where it soaked into the fabric & permanently discolored that part of the fabric. It was a sewing project & I haven't used it on satin for quite some time (plus, it was a cheapy satin from JAF -- maybe that makes a difference) as I mostly only sew quilts these days, but I still remember how devastated I was to have to pitch that fabric. I ended up re-making it & just pinking the edges.

I use Fray Block a lot in applique and regular sewing. Never had a problem with discoloration. Just be sure and don't get Fray CHECK - it dries hard.

Satin ribbon replacement
 

What about using grosgrain ribbon? Not satin like bu twould last a lot longer. Comes in various widths and is not very expensive. Diane C.