I was pumping, supplementing with formula — using several different types of nipples, and nursing — with and without a nipple shield, sometimes all in the same day! (lactationservices.com)
More accurately a baby develops a preference to a certain type of nipple for various reasons. (cathalekibclc.com)
If you're using a shield, the thin clear silicon type of nipple shield is the best to use. (kellymom.com)