I like clear plastic with flip tops - 1pd. Because the are cheap and I can use CLEAN new ones every year. Even though I appreciate the gesture - I don't like when people return to me empty jars (especially when they are labeled). I don't want to take the time to wash,sanitize and store for re-use. It is especially a PITA when the labels needs to removed. I know it is not very green of me but it's my precious time. Please nobody hate on me - FWIW: I do reuse the glass to fulfil family and friend requests.