Hi, my DD has to do an art project where she has to make a 3d letter (in this case the letter "M" and then pin things around/stick things around it starting with that letter. She has said they can use anything and has a few ideas already, including foam/cardboard. Does anyone have any other ideas please? It has to be durable/able to "stand up". Thanks! If not, I think the cardboard/foam ideas is fine, it's just that she's not sure if there's a better way?