What is the use of this item?

I've found three of these from random low-level monsters in Iria (white Mongoose outside Qilla Base Camp, Porcupines in Connous, etc.) They're not an actual sewing pattern and while the description says to take it to Simon, he does not react to it at all. He doesn't recognize it in my inventory, I'm not given a key word, I cannot use the item, and gifting it to him gives a generic response.

I really wonder, because there are Hanbok items of clothing, leftover items from an event?

More than likely, it was an unintended drop for some...unknown event.