Bags on Board Green Pups Waste Pick-Up Refill Bags make a dependable, yet environmentally friendly tool for the most undesirable tasks! They are made with natural lignin, a renewable material that is leftover when paper mills make paper. Lignin is a brown gooey glue-like substance that holds the tree together. When paper is made, paper mills separate wood into pulp (needed for paper) and lignin (typically burned by the mill). Xylomer technology converts lignin into a plastic-like bioresin material, which is used to make Green Pups Waste Pick-Up Refill Bags. Contains 8 rolls (15 bags per roll). Bag size: 8" x 13.5"