These are all VERY well preserved artifacts -- the Yingpan Man mummy is perfectly intact and the grave hadn't been disturbed at all when excavated. So we have location (under his head) and form. There wasn't any information on the stuffing (but we'll see what the exhibition catalog might say) and the precise cut of the fabric was impossible to discern since they had the artifacts displayed in situ and his head was in the way. But it was very clearly pieced together from fabric that had been embroidered for some other purpose (i.e., treated as "yardage" when making the pillow).

I'm about as certain as can be that it's chain stitch. The stitches are very neat and even (equivalent to machine-worked), and the rows of chain are distinct (especially, of course, when a single chain is used for the linear parts). More chain-stitch embroidery when I get to the wrist bracer and the pants!