Drawstring Backpack Drawstring Bags. Our drawstring backpacks are made of eco-friendly 80 gsm non-woven polypropylene. It comes with corded shoulder straps and a draw string closure. The corners are reinforced with fabric loops. The back of the bag is black and the front grey. The front pocket is being kept close with a hook and loop closure. The bright pocket is accented with a black half border to highlight your logo. The backpacks are an ideal promotional item for schools and sports teams