How old is too old for serger thread?
I was instructed by my new friends (the proprietor and the teacher at the local sewing machine place) to not use old serger thread, but then I accidentally bought some from them that was made in 2008. Seems pretty old to me! But my question is does it really matter for polyester Maxi-Lock serger thread? I'm using it on items I intend to sell, and I would like my product to stand up over time.
On a related note, if I use fresh thread, will the item I use it on break in ten years, since the thread in the product is now old? Should I make a point of using cotton thread in the needles for more durability and save the polyester for the loopers? Mostly I make bags and pants, so they get plenty of wear and tear.