 Bullock's press allowed for continuous large rolls of paper to be automatically fed through the rollers, eliminating the laborious hand-feeding system of earlier presses.The press was self-adjusting, printed on both sides, folded the paper, and a sharp serrated knife that rarely needed sharpening cut sheets with rapid precision.The press could print up to 12,000 sheets an hour; later improvements raised the speed to up to 30,000 sheets an hour.