Groundwood pulp was first manufactured in this country in the 1860's and in 20 years because of its satisfactory qualities became the major constituent of newsprint paper. In the last fifteen years a new process -- thermomechanical pulp -- has been perfected and now accounts for about 20% of the world's mechanical pulping capacity. Increased efficiency and improved characteristics will enable TMP to become more important as a source of mechanical wood pulp. -- AATA