I don't quite believe the "don't use old thread" rule is valid. I mean, if the thread was stored away from dust and direct sunlight, what's the problem?Maybe not for a show quilt. If the thread sewn into our clothes can endure the stress of wearing, seams getting pulled on when we sit etc, temperature changes from heated indoors to frigid outdoors, and WASHING (with hot and cold water and detergent) and DRYING, then why would thread that's been resting peacefully in box or drawer for years crumble? Most of the time, clothes become unwearable due to stains or wear of the fabric, not the seams. And most of our clothes are hardly couture with the finest thread. I don't think clothes sold at Target have fancy thread in them. So I'm gonna keep using my own thread stash for everything but my finest projects (and those too for appliqué). I suspect some of that "old thread is bad" argument is intended to push us to buy more thread.