Edible materials can make experimenting with 3-D printing more fun for kids. The latest technology from Ontario-based Structur3D Printing lets printers work with a wide variety of gel materials to produce everything from silicone-based orthotic shoe inserts to custom cake toppers printed from icing sugar. The technology of 3D printing machinery that carves or sculpts 3D objects from a block of material using a computer generated design has been around for years. Although fast and accurate,...