Originally Posted by Holice

Let me tell you a story about thread
Several years ago I was working as a quilting consultant for one of the thread companies. The company is no longer in business but made good thread (I still have some of it)
I was visiting a wholesale company that sold the thread and was told they were getting a lot of complaints about the thread from customers. I called my contact at the manufacturer and told him about it. He said..."our thread is of the highest quality". I said "but there are complaints being voiced about the thread. He said "wait a minute and he put me on a conference call and he called someone else in the company and the conversation went like this. "Hey Clem, this is (and I don't remember his name). He said, "hey Clem remember that bad batch of thread we got a few months ago?"
So my point is that sometime new thread is bad.
As those above have said....check and if it breaks, no matter the age, then it won't work. I have old thread that still sews well and is strong. Some new thread doesn't.