《天工开物·中篇·杀青》
造纸过程中所谓的 杀青 就是从斩竹去青而得到的名称， 汗青 则是以煮沥而得到的名称， 简 就是指已经造好的纸。
所谓 杀青 ，以斩竹得名； 汗青 以煮沥得名； 筒 即已成纸名，乃煮竹成筒。
In the paper-making process, the so-called "killing blue" is the name derived from cutting and removing the green part of bamboo, "sweat blue" is the name derived from boiling and straining, and "simplicity" refers to the finished paper.