Traditional Hmong men's jackets are made of black cotton cloth and sometimes velvet or satin. An embroidered vest like this example, with strips of colourful appliquéd cloths at the bottom, are worn on festive occasions over a white shirt.The Hmong were originally highlanders from southern China, who migrated into Northern Thailand from Laos and Vietnam during the 18th and 19th centuries. They consist of two main groups - the Hmong Deaw (White Hmong) and the 'Mong Njua' (Blue Hmong).