AI am making a 3 tired cake 12,10,8 . I want to cover it generously with icing so when i apply the fondant it has a great shape. do I go up an inch or two ? More ? What size cake boards to I get ?

Hi,

For some reason I always get confused about this...

I Think if you have a 12" cake use a 12" board w/a 10" box.

Or should you go up one size for the board and box, i.e. 12" cake, 14' board.

I know for a tied cake, the top tier boards should be as big as the cake so to hide the board once its stacked.

I use a board 3" bigger for smaller cakes, and 4" bigger for the larger ones according to the size of the cakes.
 

Personally, I always get the next size up from my bottom tier but people have varying opinions. It is really a matter of personal preference. The cake boards in my area come in 2 in increments so 1 in isn't really an option for me but once the frosting is on it, less shows anyway.

If you mean the boards to go under each tier, I get the same size as the tier.  There is room for the frosting to come just even with the edge of the board.  If you then put on fondant, it doesn't hit the board and develop bulges as it settles, and the board doesn't show.  Often I use a larger cake board, and cut it down with an exacto knife after the cake is on the board and frosted so that it is undercut just a bit before applying the fondant.   Also, I have found that a thinner coat of buttercream under fondant seems to work better.  A thicker coat may soften and shift, and the fondant is more likely to shift and settle and bulge.  It depends on how stiff your buttercream is of course.  If you are talking about the base for the finished cake, that can be whatever works with the design, but I would think would be at least a little bigger than the bottom tier.