Does anyone know offhand how many cups of filling you would need (approximately) for a 6",8",10" stacked cake?
My totally unscientific method is to figure 1/3 of the amount of frosting needed. I usually have leftover.
The Wilton chart says you'd need 12 cups of icing to ice and decorate that size cake (6"=3c, 8"=4c, 10"=5c). I'd make sure I have 4 cups of filling.