I have some thread that was my grandmother's I'm still using. I just ran across a spool a few days ago that had a price of 29 cents printed on it. I haven't tried to use it yet but you can imagine how old it is. So far I haven't had any trouble with any of the older thread. I just check it for strength before using. BTW, I'm 70 y/o and my grandmother passed in 1957.