ALL THAT GLITTERS is gold in the Textile Museum's new show of ceremonial cloths from the highlands of West Sumatra. The shimmering fabrics, most on public view for the first time, are masterpieces of the nearly lost art of weaving gold thread.

Almost as beautiful as the sarongs, shoulder cloths and head wrappings is the spirit behind them. The Minangkabau people of West Sumatra are intensely egalitarian and democratic, and the patterns of the golden threads serve as reminders of their ancient laws and customs.

It is the Golden Rule literally spelled out in golden rules, according to curators Anne and John Summerfield. The constant reminders may help explain how the Minangkabau manage to live amicably in spite of a seemingly insurmountable social contradiction: Their ancient adat, or traditional culture, is firmly matriarchal yet their religion is Islam, under which men are almost unbridled masters.

"They do a lot of rationalizing," Anne Summerfield says. "They say, 'Islam tells us what to do, adat tells us how to do it.' It doesn't make much sense on paper, but it works wonderfully well on the ground."

Minangkabau society is so community-oriented that their former Dutch rulers described their social units as "village nations," and the traditional weaving patterns each uses are as distinctive as national flags. The sense of social obligation is so strong that it's not unusual for the grandson of a villager who emigrated to some distant land to underwrite a schoolhouse or swimming pool for a community he's never even seen.

For their wedding ceremony a couple is dressed in heirloom golden fabrics that may have been handed down for a dozen generations, with the groom generally the more richly caparisoned. During the ceremony the couple crosses a cloth "bridge," half of which is woven by each side of the families being united; this symbolizes the groom's adoption into his wife's clan. Her family pays a "groom price" based on his prestige and probable earning power: A clan chief is worth most, followed by a college graduate, and so forth.

The 49 textiles in this exhibition, some of which are more than a century old, were collected by Mary Hastings Bradley in 1925, when she, her husband and her daughter were hunting Sumatran tigers on behalf of several American natural history museums. The fabrics were donated to the Textile Museum in 1985 by the daughter, Alice Bradley Shelton.

Handsomely mounted as are all the museum's shows, these golden cloths give the visitor a sense not only of the skills of the Minangkabau weavers and the antiquity of their culture but of their sense of humor. Along with the village history and social rules spelled out on one headwrapper is this homily:

"You got sugar, you got ants."

TRAILING THE TIGER: Golden Cloths of Sumatra's Minangkabau. Through June 9 at the Textile Museum, 2320 S St. NW. 667-0441. Open 10 to 5 Monday through Saturday and 1 to 5 Sundays. Suggested donation: $5. Call ahead for wheelchair access (available to all floors by elevator).