Formal Thai national costume

The formal Thai national costume, known in Thai as ชุดไทยพระราชนิยม (rtgs: chut thai phra ratcha niyom, literally Thai dress of royal endorsement), includes several sets of clothing, or chut thai, designed for use as national costume in formal occasions. Although described and intended for use as national costume, they are of relatively modern origins, having been conceived in the second half of the twentieth century.

The men's national costume is known as suea phraratchathan (เสื้อพระราชทาน Thai pronunciation: [sɯ̂a.pʰrá.râat.tɕʰa.tʰaan], lit. royally bestowed shirt). It was designed to serve as a national costume by royal tailors including Chupat Chuto, Phichai Watsanasong, and Sompop Louilarpprasert for King Bhumibol Adulyadej in 1979, and was subsequently given to General Prem Tinsulanonda, then the Minister of Defense, to promote and wear in public. Prem has remained the shirt's most recognised wearer, although it has been adopted by many, especially politicians and civil officials, on special occasions. Many have begun wearing the shirt for ceremonies such as their own weddings.

The shirt shares the appearance of the raj pattern jacket, which itself is an older widely adopted (in Thailand) version of the Nehru jacket. The suea phraratchathan is specified as having a standing (Mandarin) collar 3.5 to 4 centimetres in height, being slightly tapered at the sides, hemmed at the edges of the collar, placket and sleeves, with five round flat buttons covered with a material identical or similar to that of the shirt. It should have two outer pockets at the front, at a level slightly higher than the lowermost button, may have a left-sided breast pocket, and may either be vented or not. The shirt comes in three varieties: short-sleeved, long-sleeved, and long-sleeved with a sash, which range from the least to most formal, respectively. The long-sleeved versions should have 4 to 5 centimetres-wide cuffs of the same material as the shirt, and the sash, when used, should be knotted at the left side. The shirt is worn with trousers as would be with a suit jacket.

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