These can be obtained from Drying Washed-Up Laundry

I did now create 2 of them but... I can not sell it to the npc, what do I with that? -_-...

This is a trash item that can currently be sold to vendors. Its only use it to provide a guaranteed product for a Drying process from which we really want an item like Old Casual, which has a low chance of resulting compared to the above guaranteed trash-item result.