Preparing and using a parchment piping cone is an important part of décor work. To make a parchment cone, it is easiest to use a precut sheet of parchment paper (16 by 24 in/41 by 61 cm). Otherwise, cut a sheet this size from a roll of parchment paper. Place the parchment sheet on a flat surface with the length running parallel to the edge of the work surface. Take the lower left-hand corner and bring it up so that the point of the corner is adjacent to and level with the upper right-hand corner; it should look like two peaks of identical height. Firmly crease the fold. Insert a long, sharp knife (preferably not a serrated slicer) into the folded paper with the edge of the blade toward the creased edge and carefully cut the paper in half at the crease, using a single smooth stroke. The cut edge of each sheet will form the point of each piping cone, so it must be sharp and exact. A clean cut, not possible when tearing the paper or cutting it with scissors, enables piped icings or glazes to fall in a clean, straight line. The cone will also last longer because a clean edge will not absorb moisture as quickly as a ragged one would.