Is ear cartilage better than rib cartilage for a rhinoplasty if someone has thin skin?

Ear cartilage is a safer bet than rib cartilage. It can be shaped, sculpted, softened to give you the contour you need. Also, it can also be "crushed" to act as a filler on top of the cartilage graft to make it less noticeable! Ear cartilage is definitely the choice I would use for your reconstruction. The recovery is also definitely easier.
Good luck! 

When septal cartilage is unavailable, rib or ear cartilage can be used for grafts. The decision as to which depends on the amount of cartilage needed and the strength/type of grafts needed for the rhinoplasty. Rib cartilage is useful when in need a larger amount of grafts and those with greater strength. The thickness of the skin does not affect the source of the cartilage used; it alters the types of grafts placed. Thank you for the question. Good luck with your surgery!

hello thank you for your question and provided information as well.. based in your question its difficult evaluate you if the case dont have a picture, its recommended if you get a consultation in person with a plastic surgeon to discuss all about theme.