平印(lithography)

利用油脂与水无法混合之特性的印刷方法。布拉格人塞尼费尔德（A. Senefelder）用碳酸钙硷和细腻多孔的表面探索了石头的性质，并在1798年完成了他的印刷方法。在塞尼费尔德的方法中，以粉笔或油墨绘制设计的石头以水弄湿，在各式各样的蚀刻和保护步骤後，用油墨刷过，设计图上只有油墨保存下来。然後，把这种上墨的表面印出--用特殊压平器直接印在纸上（例如大部分的美术版画制作），或者印在橡胶滚筒後再印在纸上（例如商业印刷）。手工印刷的石头制备方法仍是艺术家偏爱的平印法，至今几乎没有改变。现代轮转式胶印压平器的商业平印能够快速制造高品质、细腻的印刷品，复制任何可在制版过程中拍摄的材料。现在，它占了所有版画、包装、印刷的40%以上，比例是其他所有单一印刷方法的二倍。

English version：

lithography

Printing process that makes use of the immiscibility of grease and water. Aloys Senefelder of Prague (1771-1834) exploited the properties of a stone with a calcium carbonate base and a fine, porous surface, and perfected his printing process in 1798. In Senefelder's process, the stone, with a design drawn on it with crayon or greasy ink, was wetted with water; after various etching and protecting steps, it was brushed with oily ink; it retained the ink only on the design. This inked surface was then printed—either directly on paper, by a special press (as in most fine-art printmaking), or onto a rubber cylinder and thence onto paper (as in commercial printing). The method of preparing stones for hand printing, still the lithographic method preferred by artists, has hardly changed. Commercial lithographic printing on a modern rotary offset printing press can produce high-quality, finely detailed impressions at high speed, reproducing any material that can be photographed in the platemaking process. It now accounts for more than 40% of all printing, packaging, and publishing, more than twice the percentage produced by any other single printing process.