When using moulds with icing fondant it is best to lightly dust them with cornflour rather than icing/confectioners sugar. This is because cornflour sits on the top of the mould and ensures the icing does not stick allowing it to release easier.
Icing sugar or confectioners sugar is known to absorb into icing and can cause the icing fondant to stick in the ridges of the mould.
Cornflour is also known to leave dust marks on dark colours such as black, red, green etc therefore if you do use icing sugar with your moulds then try the following tip for additional help.
Tip – If your icing is very soft or warm and sticky and you find it is tearing when you try to remove your icing fondant from the mould then simply place the mould with your icing fondant into the freezer for about 10 minutes. This allows your icing to harden and peels out of the mould much easier.