信封起源于两千多年前的秦汉时代。当时,文书和书信大都是刻写在木板和竹简上,为了保护书信完整无损,就用两块刻成鲤鱼形的木板,夹在文书简牍的外面。木板上还刻有三道线槽,用绳捆绕三圈,然后再穿过一个方孔缚住。在线端或交叉处加以检木,封上黏土并加盖印章,以防私拆。这就是中国历史上最早的信封。魏晋以后至南北朝时期,书信材料逐渐由木质演化为纸质。信 Envelopes originated in the Qin and Han dynasties more than two thousand years ago. At that time, most of the clerical and correspondence were inscribed on planks and bamboo slips. In order to protect the correspondence intact, two pieces of carp-shaped planks were used and they were clipped to the outside of the clerical. Also engraved on the wooden three trunks, tied with a rope for three laps, and then through a square hole tied live. At the end of the line or intersections to check wood, sealed with clay and seal, to prevent the private demolition. This is the earliest envelope in Chinese history. From the Wei and Jin dynasties to Southern and Northern Dynasties, letters and letters gradually evolved from wood to paper. letter