Dry Bags - A dry bag is a type of bag which seals in a watertight manner. Dry bags are often used in kayaking, canoeing, rafting, and other outdoor activities where sensitive items would otherwise get wet. They are often a construction of plastic film, plastic-coated fabric or waterproofed fabric which is formed to create an impermeable, water-ingress protected bag. When using a dry bag, it is vital to ensure the roll top closure is folded at least three times, to create a watertight seal. Construction techniques include welding, sewing (where a seam-tape is used to seal over any needle-holes) and gluing.