Why are industrial paper sacks so tear-resistant and how is a typical sack constructed? How can the tear-resistance be determined? Erwin Polman from Papiertechnische Stiftung (PTS) in Munich, Germany, answers all important questions concerning the tear-resistance of paper sacks. The paper and packaging expert provides useful knowledge and informs about the advantages of paper sacks compared to plastic sacks. This video made by Gemeinschaft Papiersackindustrie e.V. (GemPSI), is part of a four-episode series about the tear-resistance of industrial paper sacks.