To add durability, use a heating tool to slightly melt the edges of seat belt webbing. This will help to prevent fraying of the webbing and increase its overall durability. Measure and cut the seat belt webbing into the desired length. To prevent the webbing from shifting, pin or clip http://pandora.nla.gov.au/external.html?link=https://www.ledteks.com/seatbelt-and-safety-belt-webbing