I ave been saving Trader Joes Organic Marinara jars over the past year. They have "Mason" in raised glass near the top rim and so I, mistakenly, thought they were canning jars. They aren't. They are slightly smaller than a narrow-mouth jar, so slight that it wasn't noticeable until I tried to put the band on a jar that I couldn't get my Foodsaver to vacuum seal.

I'm glad I found out before I tried to pressure can with these jars. I was talking to someone who said they would NEVER use a store jar for canning and I wouldn't either, typically, but I guess I was led (or misled?) by the "Mason" on the jar.

I've written to Trader Joe's but I would also like to write to the mfg of the jar. Is that Ball? Because I've googled and haven't had any luck that majes me absolutely positive that Ball is the right direction to go.