A pulp and paper mill which is self-contained as regards its fibre; i.e. a pulp mill which produces pulp exclusively for the on-site paper mill, and/or a paper mill which sources all its fibre from the on-site pulp mill. A "partially integrated pulp mill" is a pulp mill which produces more pulp than is required by the on-site paper mill, selling the surplus on the market. Likewise, a "partially integrated paper mill" is a paper mill whose pulp requirements are only partly met by the on-site pulp mill. The deficit is purchased on the market.