Which character? Vil Schoenheit, world-class supermodel-
What do they want? Anything Jesper can make from these, from their meeting this is what he'd have first asked for since it's useful. But some lighter outfits, robes he can wear and adjust into different styles would be grand. He will also! Help make them.
Can they supply materials? Yes!!
What are they trading? A beautiful apprentice- but really, whatever Jesper needs in materials and also his skills. He'll happily sew with him and help him out.