My friend was asking me if it would be possible to pipe a floral design on poured ganache. I assume after it sets up that would be fine, but out of what? Royal icing, buttercream, melted chocolate?

I've used whipped ganache before. I made a kitchen cake to go with a groom's cake I did a couple of years ago and I just put whipped ganache in a pastry bag and did some large filigree design on it. No one really saw it, because it was cut in the back, but it looked nice. I didn't think to take a picture of it then!

If you're like me and don't have a steady hand you could pipe a royal filigree on wax paper, let it dry and then add it to the ganache. To me just the smooth surface is beautiful if it's shiny.

I was on you tube and saw someone make a beautiful royal icing collar to put on top of a cake. It was lovely.

Those are both good suggestions. My friend is shopping around for her wedding cake, and I'm her back up if she can't find what she wants. She's looking for a dark chocolate poured ganache on 2 tiers, and white chocolate poured ganache on the other 2, alternating colors. Then some type of simple decoration, swiss dots, small filigree, or floral pattern with a "w" on top. So I'm just trying to give her an idea of what to ask for even. My other question, before pouring ganache, would you do a thin crumbcoat first with spreadable ganache? That way there is a much smoother surface to pour over? Or do you think poured straight would be best...