I am making a light blue cake with small tip piping swirls all over it with white orchids. Should I use Royal Icing or Buttercream? The cake will be outdoors in June in Michigan.
What will the cake be iced with? (ie fondant, BC, etc)
Buttercream and the cake will be put in a fridge and then sit outside.
Buttercream should be fine as long as it's one that can deal with the heat and humidity. HTH
If you are using buttercream icing, there is no need for you to pipe in royal icing. Its better to stay with buttercream.
With the heat, the grease released from the buttercream covering combined with condensation from the humidity in the air will RUIN royal icing--quickly!