A yếm is a traditional Vietnamesebodice used primarily as an undergarment that was once worn by Vietnamese women across all classes. There exists a modern variant called the áo yếm, but the historical garment was simply called a yếm. It was most usually worn underneath a blouse or overcoat, for modesty's sake. It is a simple garment with many variations from its basic form, which is a simple, usually diamond or square-cut piece of cloth draped over a woman's chest with strings to tie at the neck and back.
History
The yếm originated from the Chinesedudou, a variant of similar undergarments used in China since antiquity whose use spread under the Ming and Qing dynasties. It became popular in northern Vietnam. Unlike other Vietnamese clothing that helped to segregate the classes, the unseen yếm were worn as an undergarment by Vietnamese women of all walks of life, from peasant women toiling in the fields to imperial consorts. It is an integral part of the áo tứ thân costume, which it is often worn underneath. The skirt which is worn with the yếm is called váy đụp. Chinese-style clothing which was forced on Vietnamese people by the Nguyễn dynasty took the place of the yếm and skirt. Trousers have been adopted by White Hmong. The trousers replaced the traditional skirts of the females of the White Hmong. The tunics and trouser clothing of the Han Chinese on the Ming tradition was worn by the Vietnamese. The áo dài was created when tucks, which were close fitting and compact, were added in the 1920s to this Chinese style. Trousers and tunics on the Chinese pattern in 1774 were ordered by Nguyễn Phúc Khoát to replace the sarong-like traditional clothing. Chinese clothing in the form of trousers and tunic were mandated by the Vietnamese Nguyễn government. As late as the 1920s in Vietnam's north area in isolated hamlets skirts were still worn. Chinese Ming-, Tang-, and Han-style clothing was ordered to be adopted by Vietnamese military and bureaucrats by the Nguyễn lord Nguyễn Phúc Khoát. Pants were mandated by the Nguyễn in 1744 and the cheongsam inspired the áo dài. Chinese clothing started influencing Vietnamese dress during the Lý dynasty. The current áo dài was introduced by the Nguyễn Lords.
Different types
While it was worn across classes, the material and colors used to make yếm varied widely based upon the person's social status and the occasion. Commoner women usually wore yếm in simple blacks and whites for day to day use, whereas during special occasions they could opt for more festive, brighter colors such as red and pink. Indeed, much of Vietnamese poetry has been dedicated to the beauty of women in their vermilion bodices. While the bottom of the yếm are v-shaped, there were different styles for the top of the garment which covered the neck, the most common two variations being the rounded neck or the v-shaped neck style. Some types of yếm have a little pocket within, where women often used to store a little musk or perfume.
In modern Vietnam
As Westernization reached Vietnam, by the 20th century women increasingly abandoned yếm for the Western bra. Fashion designers, in their constant quest to revitalize interest in traditional costumes - as well as reinvent them - have created many new collections of yếm. The modernized form of the garment is slightly different and is called "áo yếm" rather than "yếm", the latter referring to the historical garment. Áo yếm has proven to be quite popular with young women, perhaps due to its similarity to the Western halterneck.