sometimes if you place the ribbon on ahead of time then the crisco will get a chance to stain the entire ribbon giving it a uniform look again. No an appealing idea, but it works, and no one can tell that it's grease stains and not the actual ribbon color.
I cut a thin strip that's smaller than the ribbon of wax paper and tape it behind the ribbon. I wrap that around the cake and didn't experience any problems with oil soaking through it
I use organza ribbon, and have no problem whatsoever with the buttercreme staining. The organza costs more, so you would have to charge more. Hobby Lobby and Hancock fabric (not sure if they are a national chain) run sales on organza ribbon all the time.
Actually only tiered cake I have ever done with ribbon has been for family.
HTH, Cindy
Something else that can be used to help with the absorption is freezer paper. Cut a strip of freezer paper a tiny fraction less than the width of the ribbon and iron the shiny side of the paper to the wrong side of the ribbon. This offers a little more crispness and stability for the ribbon and will help with the grase stains. It will obviously show through sheer ribbons, though. Be sure to test your ribbon before you pop a hot iron on a synthetic fiber and melt it 
. You may need to use a press cloth.
Thank you all sooooo much for all your advice. I will be trying them until I get it right. And Mendhigurl, you are exactly right. That was the 1 thing that saved me. The entire ribbon absorbed the grease evenly. And again, thanks to all of you.
I love this site 
I can't do my work for looking at this site EVERYDAY at work. sssssshhhhhhhhh 
Quote by @%username% on %date%
%body%