I am unsure how much royal icing to make for a 12 inch heart cake?? Does anyone have a good royal icing reciepe?

What are you using the RI for? I use the royal icing recipe found here under the recipe section!

I want to cover a heart cake for a wedding shower. Someone had told me that Royal Icing covers nice and evenly?

are you planning on covering the cake in royal icing? royal icing tends to get quite hard and crunchy and doesn't have a *great* flavor. most people use buttercream or fondant... better flavor, doens't harden up as much.
Royal is generally used for decorations and embellishments (flowers, plaques, colorflow, letters/numbers, etc).
HTH
Jill

I just printed out that recipe...thnxs

Thank you for that info....but the person I am making the cake for does not like buttercream?

Dont cover the cake in RI is hard and it will crumbe when cut, It's a big NO NO, just for dummy cakes

You can use Royal icing to cover cakes ..I have a few cake deco books and web instructions that use Royal icing to cover. You have to add Glycerine (glycerol) to the icing which prevents it from setting too hard.

HTH