How long do sugar cookies with royal icing stay good for?

[vanity021]

I am planning on making Cookie Invitations for my daughters birthday but wasn't sure how much in advance can I bake them and they will stay fresh?

I plan on putting either royal icing or dipping them into white chocolate to decorate.

[JoanN]

Sugar cookies with royal icing can last several months if stored, layered between waxed paper, in an airtight container. Don't know how well white chocolate holds since I don't use it much.