YouTube needed a video tutorial on using dental floss, fishing line or strong thread to cut sheet cakes. eHow has floss information. YouTube has a few examples of how to use an warm knife wiping it off with each slice - proof that this method is easier and leaves the icing and most decorations looking nice. With slight modification and careful planning any shape cake can be cut with this technique. Be sure to use a knife or server between slices and under the icing to separate the slices completely. If it doesn't work - you did something wrong!