Well, I did it. I always say yes to a cake and the figure out how to do it later. This one has me stumped though this time.  Not quite sure on how to make this look. I think it's just a spatula drugged through the icing, but not sue how to make it this smooth.  Any ideas would be appreciated.

Pls re-post picture or a link to what you are referring to...

We can't help without seeing the picture:)   Please upload the picture into you photo gallery, then post the link to it.

 http://www.cakecentral.com/gallery/i/3343218/how-to-do-this-cake

Sorry thought I had the picture with the text, thanks for your help:) 

It takes practice. I advise that you do not experiment on paying clients.

You have to have very smooth. creamy b'cream icing and a large rose tip to pipe those ribbons.

Practice some to see if you can pull it off.  We don't know your skill level and hopefully you will be 'man enough' to tell you customer you can't do it if that's how it turns out.

To me it looks like a fondant cake - you can see the occasional glue line under where the ribbons meet.

As a fondant cake it would be extremely easy.  Take your buttercream/ganached cake and add ribbon strips of fondant from the bottom up, overlapping each ribbon as you go.  The back would have the all the joins, which could be prettied up with a pearl/button/blossom or vertical fondant ribbon.  The top of each tier has a fondant round which is ever-so-slightly larger than the cake, so it overlaps the edge of top ribbon.

It looks like  fondant to me, there is a lady that  gives a class on this on Craftsy....its rather easy,,,good luck

I think I've seen this before. If I remember correctly, they took a thin plastic scraper and cut teeth in it to make this pattern on the buttercream cake. Each tooth was straight across on the bottom and then angled up. I don't think it's fondant. 

i wish I could find the tutorial that I saw. if I find it I'll post it  

Piped.

*drugged through the icing? I'm not sure what that means.

Thank you for all the ideas! I am going to practice with pipping with large rose petal tip, they requested no fondant.  Jedi Knight- I was originally thinking that I would ice the cake with the ombré then take a spatula and put in on an angle, and remove icing( drag the spatula through) tried it later in The day and it wasn't the look I was looking for. Thank you again, I got till August to perfect it. 

Yes, it could be ribbons of fondant but the OP stated they wanted b'cream thus the use of a large rose tip (OR tip 105 - which is sometimes called a carnation tip but I don't think it will yield a wide enough ribbon).

I would try piping the buttercream with Wilton tip #789.  I think this will give you wider bands.

http://cupadeecakes.blogspot.com/2013/04/buttercream-comb-cake-and-comb-tutorial.html

This is the tutorial I was thinking of. Good luck on your cake. I'm sure it will be beautiful!

I want to thank  everyone for their advice. After many modifications and a couple practices last weekend I think I'm happy with the results of this weekend's practice. What do you think?  Thanks again! 

Looks pretty good to me.  Love the ombré look.

Meant to say I love the ombré look.  Darn auto correct. ;-)

Sorry, it keeps changing the word when I hit the submit button.  Hope you know what I'm trying to say.