In this paper, we analyze the diffusion and adoption of paper making machinery in the indonesian pulp and paper industry, from 1923 till 2000. We develop a machine level index of technological sophistication (mach), which measures the technological distance of each paper machine to the world technological frontier. The data reveal a pattern of rapid technological catch up. But catch up was not an industrywide phenomenon. Some modern firms installed state-of-the-art machinery, while others installed older vintages. The paper argues that industrial policy has played an important role in the speed and nature of diffusion of paper making machinery.