This is one of about 30 I have that I inherited from my grandmother in law, an antiques collector and dealer. There are certainly reproduction jars out there that were recently made, but they have a few differences. On the new ones--They were made starting in 2013 in pint size only, not sure if they have started making the larger ones also , have this on the back: “1913 1915 / 100 YEARS OF / AMERICAN / HERITAGE / MADE IN U.S.A.” . Also, there are volume/weight measurements embossed along the side of the jar, including cups, milliliters and ounces. They are being sold along with modern screw bands and lids. The glass is a bit thinner and lighter than the original Ball Perfect Mason types, they are colored a lighter& brighter blue than the originals, and there will be a registered mark near the Ball logo. If you would like to see an excellent chart for identifying the age of your ball jars , check out my last photo. ;)