Hi I was wondering if anyone could advise me please. I am doing my daughters three tier wedding cake with royal icing. I am going to marzipan them all this week to let them dry out. And was thinking if I could start putting the first coat of icing on next week.? The wedding is 11th June. Then the second and last coat on about 10 days before approx.?
Plus if I put more glycerin in to the icing would it stop it going too hard before the day.? Have been told one teaspoon for 1 lb icing.

Why are you doing it so far in advance? Glycerin will keep the RI soft, but I'm not sure of the amount. I'm no help but here's a bump!

I'm guessing OP is overseas and is doing a fruit cake which is generally done way in advance so it can be soaked in alcohol.