After the Trịnh-Nguyễn war, the residents in Quảng Nam (Canglan – the Southern) began to adapt to some customs of Champa, one of those was "vấn khăn" – wrap the scarf around head.
In 1744, Lord Nguyễn Phúc Khoát of Đàng Trong (Huế) decreed that both men and women in his court wear trousers and a gown with buttons down the front.
From 1830, Minh Mạng emperor mandated that every civilian in the country change their clothes and that custom became popular throughout Vietnam.
[citation needed] Khăn vấn is a rectangular textile that is long and quite thick, wrapped tightly around the head.
In addition, according to the law of Nguyễn dynasty, the problem of being too short and thin was prohibited, but too long and thick was also criticized as ugly.
[5]In the old days inner Imperial City of Huế, phấn nụ (face powder made from flower mirabilis jalapa) and khăn vành went together.
The nhiễu cát textile, woven by Japanese in the past, was only half as thin as the Crêpe de Chine, which was used in the Imperial City at the end of the Nguyễn dynasty.
A khăn vành dây made of the imported textile crêpe de Chine is 30 cm wide, has an average length 13 m. A khăn vành dây made of Vietnamese nhiễu cát textile is nearly double the length.
Half the width of the scarf is folded, starting at the nape, leaving the open edge facing up before continuing.