Many of my jars are quite old, and yes, I do think some are a little thicker. I don't pressure can, but I've been using my jars for years and years.

I don't pressure can any more, but I have in the past from jars I got years ago at yard sales or were given to me. Some are even old blue jars. Bought a few newer at that time jars, Occasionally I would lose one, but probably as many of those were new ones as the old ones. About all I can now are in water bath, haven't lost one in a long time. Just double check the edges of the rim to make sure no little chips or anything before wasting your time with it.

Using old jars discussions

I also have boxes of old jars, I'm still canning in Grandma's old jars, and in jars I got from my girls' "church Grandmas". I have a collection of really old jars, including some Drey, Atlas, Mom's, Presto, blue and green Ball/Kerr jars, odd and discontinued sizes. I also have various jars from marshmallow Cream, spaghetti sauce, pickles, etc., and the current rings and lids fit perfectly. I don't pressure can with them, as I did find I get more breakage than usual. Even the government now says it's OK, when it was "not recommended" before.

I check carefully for cracks and chips, and then use them. It's the ultimate in recycling.

Annie

I started canning in 1975. My mother-in-law taught me how that year and gave me a dozen pint jars with the bicentennial logo 1776-1976 on one side. I treasure these, don't give them away, and have canned blackberry jam in them for many years ever since. The blackberries aren't like the wild ones we used then when we lived in Oregon, I think those were actually Marion berries. The two jars with a nick on the rim hold my extra pocket change and have a red white and blue ribbon around their neck. Pleasant memories. Ultimate recycling.