Pulp-making plant. Wood-digesting tanks in a paper mill. These tanks turn wood into pulp - the semi- liquid material from which paper is made. Raw wood is chipped and fed into the digesters, where high- pressure steam and chemicals make the wood fibres separate. The resulting pulp is then bleached to make it white and poured out into flat sheets to let water drain away. The sheets are pressed and dried to make paper, which may also be coated with clay or chalk to make it smooth. Photographed in Canada.