I don't know if this is the correct forum and would be OK with it being moved.

A guest wants to purchase bolts of pashmina cloth (silk, silk/cotton mix) to make pashminas for export in Chiang Mai. Any refererrals??

Pashmina is actually cashmere or at the very least a piece of material with cashmere in the blend.

Your best place to start of would be the fabric shops around Warorot market. Many of the shops are managed/owned by people of Indian nationality/heritage and they can speak English and advise you of the content of the fabric.