Drawstring Backpack Drawstring Bags. Our Polyester drawstring backpacks are made of 210 Denier Polyester, corded shoulder straps and a draw string closure. The backpacks have a 11 1/2" W X 12 3/4" H imprint area and are an ideal promotional item for schools, sports teams, camps, and clubs. Choose from among the vibrant color options and have your company name; logo; or promotional message imprinted