Most of our cardboard shipping boxes are made from recycled materials, such as old cardboard products or sawdust and woodchips. Corrugated cardboard can also be recycled to produce cereal boxes, paper towels, tissues and writing paper. Don’t recycle wet cardboard as this can clog the sorting machines at the recycling plant. Similarly, pizza boxes can’t be recycled because of the grease that soaks into the cardboard from the pizza. The same goes for paper plates, napkins and paper towels that have food or grease remnants. Glossy magazines can, in fact, be recycled. New technology has allowed shiny magazines and brochures to be recycled into newspaper, tissues and writing paper.