Ao Yem

Ao Yem, also referred to simply as "Yem", is an ancient Vietnamese bodice used primarily as an undergarment that was once worn by Vietnamese women across all classes.

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.

The Ao yem has always existed as an essential part of the Ao tu than costume worn by northern Vietnamese women, which itself has existed since at least the 12th century. Unlike other Vietnamese costumes in feudalistic Vietnam that helped to segregate the classes, Ao yem were worn as an undergarment by Vietnamese women of all walks of life, from peasant women toiling in the fields to imperial consorts.

While it was worn across classes, the material and colors used to make Ao yem varied widely based upon the person's rank and the occasion. Commoner women usually wore Ao yem  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 "Yem dao", or pink bodices.

While the bottom of most Ao yem 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, known as "Yem co xay", or the deep v-shaped neck style, called "Yem co se".

Another type of yếm, known as "Yem deo bua" has a little pocket within, where women often used to store a little musk or perfume.