I have tried to craft both Wu's fighting collar and sash and I have been told on both recipes that "You cannot combine these items in this container type!" when I used both my Large Sewing Kit and in the loom in East Freeport in the upstairs of Velith and Bardo Imported Goods. I have used 1 vial of viscous mana, 4 unstacked heady kiola, a gorget or belt pattern, and 1 silk swatch for the collar and 2 for the sash. Here are some relevent links I could find.
http://web.archive.org/web/200108151...fighting_armor
http://web.archive.org/web/200211181...tml?recipe=157
http://web.archive.org/web/200211130...tml?recipe=152