What is the best powder to use for rolling out coloured fondant? I recently used cornflour in a trial run for a cake with purple fondant, and some of the flour stuck in the little cracks and didn't look so great.... Should I use icing sugar? A book I have recommends cornflour over icing sugar because the icing sugar can go sticky?? What do you recommend?

TIA :O)

I always used 10x powdered sugar, never had a problem

I use cornstarch but I steam all of my cakes and that removes any traces of the cornstarch.

Thanks, how do you steam a cake??

I don't use either one. I use a small amount of vegetable shortning on the mat to roll the fondant out on, no sticking, no dusty fondant.