I need some help. I am attempting to cover a square piece of cardboard with black fondant for the mortar board part of a graduation cap. It's not going so well. Do I need to use icing or something to make it stick or should I wrap it and let it sit. I tried once, picked it up, and all the fondant on the bottom where I folded it in just fell down.... grr. I need help!! Thanks!

You can probably use icing. I just sort of pinched all the edges by running my fingers down each edge. This gave it a crisper look, and helped keep it in place

If you have enough time to let it dry you can just skip the cardboard all together. Just add some tylose powder to your fondant/gumpaste, roll it out thick and let it dry. I smoothed the edges of my cap with my finger to soften the edge a bit and it turned out great!
Good luck!!