Dorf is demanding an endless amount of cloth for his artifact Tried spawning in a few bolts of cloth with DFhack to try and diagnose. Dorf seems eternally stuck fetching more silk. Initially, he would go silk/wool/silk/wool. I spawned in enough silk to match the amount of wool, thinking once he had all of both it would clear the loop. It did, a bit- he went for the next ingredient, some leather, then right back to silk only.

EDIT: After some digging, it seems related to the guildhall zone designated over the workshop. After erasing the zone covering the workshop, the loop cleared with the next gathering of ingredients and the item was successfully created.