Some might have seen my other post regarding my wedding cake yesterday. I don't know how square/sharp you can really get with fondant, but I find when the cake starts coming to room temperature as the buttercream softens, my edges soften. How can I avoid this? Am I using too much BC under the fondant?

Inspired by Michelle has superb suggestions on her videos/blog:

How to Cover a Fondant Cake to get Sharp Edges
http://www.inspired-by-chocolate-and-cakes.com/fondant-cake.html

She uses chocolate ganache instead of buttercream.

The only time I have ever gotten easily sharp edges is with Satin Ice fondant. It rolls thinner than my homemade fondant ever could. It rolls almost paper thin. It was amazing. Not even WIlton fondant rolled that thin for me. I use a crusting BC which doesn't soften in the heat. You need to try a BC that has shortening in it. Half shortening at least.

HI, if you will google that same question, you will see great videos and tutorials on this question. It will truly help you. I have watched them in the past and looked for this answer also.

There are 2 videos on my Youtube channel that illustrates how we cover a cake with fondant (buttercream underneath) and how we get sharp corners on your fondant covered cakes. Link is below. Hope it helps.

Minette

I use cake spackle, then a thin layer of non-crusting buttercream. Roll my Fondx about 1/8" thick thick on a silicone mat VERY LIGHTLY coated with shortening. Then, I invert the fondant along with the mat over my cake. Lift off mat by holding each side taught and peeling back starting at the far side. I smooth the top, followed by the top edges, then adhere the fondant to each of the 4 corners. After corners I smooth out each side of the cake. Once all the pleats are out, I use 2 fondant smoothers to crease each edge and corner, finally I trim the excess fondant off the bottom edges.