Adhesives are used in many timber-based products. Adhesive manufacture starts with crude oil or natural gas. These are converted into interim products which in turn provide the raw materials for adhesives. Such processes are very resource-demanding. Even if the adhesive only makes up between 1 and 2 per cent by weight of a glue-laminated product, and between 10 to 12 per cent of chipboard, the energy consumption involved in the manufacture of the adhesive constitutes almost 10 per cent of the total energy used in production of the laminated product and 30 per cent of that used in the manufacture of the chipboard.