Line type thermal printing method onto plain paper is developed. In this method, a thick-film thermal print head which has partial glaze is used. As a result, good contect between ink and paper is realized. And, a type or a property of ink is optimized. Using this method, a page printer whose performance is nearly equal to laser printer is developed. Resolution is 300 DPI. print speed is 4 pages per minute, and good printing onto plain paper is possible.