never simply 'assume' I've used thread that my mom bought in an estate sale 20 years ago that is still just fine- do a strength 'tug-test' to see if the thread is still strong- or if it breaks easily when you hold a strand of it between your two hands & give it a tug. I've had brand new thread that was- *garbage* and old thread that was wonderful- wood. plastic, cardboard- what ever does not have a lot to do with it- the way it was stored, where, and the thread itself will determine if it is still good or not.