Anyway, serendipity struck, and I walked through both Pahurat and Sampeng markets looking for a moneychanger.
Pahurat and Sampeng markets are sewing heaven. Pahurat is one of those buildings that is bigger on the inside than on the outside, and Sampeng seems to go on for miles. (It only goes on for blocks, actually.) Shops selling buttons, zippers, ribbon, and notions of all kinds, and some finished clothing.
And fabric. Fabric as far as the eye can see, which admittedly isn't very far because everything is so tightly packed together.
Over lunch at a food stall, I realized that I had a lot of friends who would have a blast here. And then it occurred to me that a lot of them would probably want to see the Morning Market in Vientiane, and maybe the silk in Chiang Mai, and maybe Little India in Singapore, and so on. And there was the weaving in Luang Phabang.
There are a lot of fabric markets here, some of them for tourists, and some for local people. Pahurat and Sampeng didn't have many tourists. I think a lot of people locally either make their own clothes, or buy fabric to have them made, since labor is cheap.
I don't know the first thing about fabric or sewing, so I wouldn't be able to give any detailed help about the material. But I imagine I could bring people to the markets and say, "Look! Fabric!" :)