One piece is a yellow cloth with traditional markings and floral prints. It is so exclusive that it can be worn only by a monarch or a royal highness by birth during grand ceremonies, such as a coronation. The other piece is a breast cloth.

The exhibition of the two textile pieces and a collection of rare clothing and ancient fabrics will be held to honour His Majesty's 80th birthday on December 5 of next year.

Curator Somchai na Nakhon Phanom said His Majesty graciously presented both fabrics to the museum in 1952. The yellow cloth seems to have never been worn or used at all, while the breast cloth had creases from folding.

The museum used a special technique to restore the breast cloth to its original appearance.

He said the other garments were rare and old, going as far back as the late Ayutthaya era. Most other fabrics belonged to ancient kings and were stored in palaces. They ranged in age from 50-100 years.

An image of the yellow fabric can be viewed at the museum's website, www.bangkok-museum.go.th.