I've been doing some researches into differnt styles of hanfu worn in various Dynasties and what they look like. I came upon Ming Dynasty and the description of yunjian being one of the clothing that's is often worn by the citizens. I find them interesting and decided to share them here as a brief history to leanring how yunjian came to be.
What is yunjian?
Yunjian (云肩), also known as a shawl (披肩) is a type of clothing decoration that developed after the Sui Dynasty. It is mainly made from materials such as silk and satin brocade, taking on shapes such as clouds or having clouds embroidered onto a cloth.
Its purpose when first integrated into everyday wear isn't simply just for decorations. But with time and as the popularity of yunjian rose in the Ming and Qing Dynasties, it gradually became a part that added depth to what is being worn, like pendants or necklaces - and added decorations to the overall looks.
If laid out on a flat surface, yunjian's shape is quite similar to a donut. Only the part facing the front will have a split so when worn it wraps around the neck and rests against the shoulder. Unlike many shawls that we know of in the modern era, most of the yunjian will be resting on the shoulder or slightly protruding from where the shoulder ends. If it's made from softer materials, it will droop down the shoulder. But it won't be reaching past the chest area. And at the front, there will either be some sort of clip, button, or (mainly) ribbons in the inner circle that will tie the split together to prevent it from easily slipping off the shoulder.
History of Yunjian
There is no exact era in which yunjian was created and used by people. Some say that its influence was brought by nomads from the North to the South and then got created into something physical. But there is not much support beyond this saying.
The earliest existing evidence of yunjian is mostly on murals, where it appears on immortal's outfits. Such as “Dunhuang Tang Dynasty” murals, where yunjian appears on bodhisattva. Chinese descriptions of yunjian usually follow with a saying “雨后云霞映日， 睛空散彩虹。” It describes the spectacular view after rain where the cloud reflects the sun, and as the sky cleared various colors of the rainbow will be seen.
The people draw yunjian on gods not only to add beauty to beings in their mythologies but also to represent what humanity yearned for. And what they yearned for is the ability to ascend to the immortal realm. Yunjian in this case presents the god to have their shoulder surrounded by colorful clouds as if in heaven and also whatever is attached to the edges of yunjian will give whoever is wearing it a more flowing, elegant look.
It's only when a female clay figurine from the fifth generation of Southern Tang is uncovered and wore yunjian above their clothing do people nowadays be able to make a rough estimation on when yunjian became something physical and that humans started to wear it as clothing than simply it being for immortals.
When it's first created, its main purpose is to keep dandruff, dust, or oils from staining the area under the next. (You can compare it to a baby's bib).
It started as a simple one-piece of clothing sewn together, expanding in four directions (四合如意式). That is the most common of yunjian, included with cloud shapes or embroidery on all four directions of cloth. Later on, people started expanding the direction, from four sides to eight or more. This symbolizes ancient people's strong belief in different sayings but also their admiration of the sun. With this, more shapes and embroideries started appearing on yunjian besides clouds. Along with that, people also start adorning yunjian with tassels and bells so that it goes beyond simply being a cloth that ties around the neck, but has its drooping end moving along with one's step and bodily movements.
Sometimes the pieces of yunjian won't even be sewn together completely. Only connected with a thick thread of silk so that the pieces are freer to move with the wind and movements.
As for the name of yunjian...Not sure if the people called it Yunjian when it was first integrated into civilization. But it only started appearing on records during the Yuan Dynasty.
When yunjian got created and worn by humans, it was mainly worn by nobles. It was only around the Ming and Qing Dynasty that yunjian reached every one of various statuses and ranks and can be worn with everyday wear. And as it popularized, people started combining yunjian designs and patterns with Tang Dynasty male outfits and named them 云肩通袖膝襕, basically Tang Short but with design on the shirt.
Gradually, yunjian became an outfit decoration that is indispensable for women on the day of their marriage. Even now, people still hold this concept of a red wedding dress being paired with yunjian around the shoulder if the wedding they held took on a more historical and ancient theme.
Besides that, yunjian is mainly paired with Ming Dynasty clothing for women, often with stand-up collared tops (long or short) or long gowns and with Ming skirts.