The Aluminum core of this Plastic laminated twist tie material is lightweight, flexible and non-magnetic. The #321 spools are constructed with two layers of laminated plastic with an aluminum core. The flexible core and plastic laminated sheath wrap around products to be tied. From the Food Industry to the Industrial Marketplace, our Aluminum twist tie spools provide the proper closure for your products. The standard color in stock is white, but a multitude of colors are available at your specific request.