I get most of my canning jars at yard sales, rather than buying them new. I have one odd-sized jar, wondered if anyone has any insight on it. The diameter of the top is in between wide and regular (diameter of top is 3". The height is 5 1/2", and it's straight-sided. Before you say maybe it's just a mayo jar or some such. . .it says "Ball" in their trademark kind of diagonal cursive writing on the bottom. Ideas? Interesting.
I have one stright sided jar also but the regular wide mouth lids fit it I wish I could find more they are a quart jar and are a lot easier to fill and get the air out. And the take up less space because they are stright sided.
There are a lot of peculiar sized old canning jars out there, I save lids fro other jars that I can occasionally match up with one of the older jars, I love old canning jars.