Premade rollable icing is disgusting. Royal icing is actually much easier to ice with if you finish it with a spiky snow effect instead of trying to smooth it like a wedding cake.
Depending on the type of icing fondant can be used immediately, royall icing needs about a week to dry. Sorry im very late giving you this info but you'll be well prepared for next year.😄 merryChristmas
@Ann Britton haha your Fine, I have made 6 Christmas cakes this year, I let marzipan set for 24 to 48 hours and I let the ready to roll fondant set for 48 hours an all worked out 😁