Return to every fabric roll you used
First check whether the piece was cut but left on a fabric section instead of being moved into inventory. Inspect the full cutting surface and each material used for the design.
Count the design against inventory
Compare the sketchbook components with the panels already on the mannequin and the pieces still in inventory. In Build 410, the inventory hover hint identifies the intended mannequin location.
Save and reload once
Multiple players report that a missing cut panel returned after saving, leaving the game, and loading again. Treat this as a workaround for a suspected bug, not a guaranteed mechanic.
Escalate a repeatable disappearance
If the piece disappears again, capture the pattern name, fabric, action immediately before it vanished, active commission, and build number. Those details distinguish a missed panel from a reproducible inventory fault.