|I know it's conventional wisdom - if thread is so ancient, it's on a wooden spool, it's probably too deteriorated to use. And I'm sure that's correct to toss it in many circumstances...
But I found lots of uses for this 'useless' thread. I got a vintage sewing basket loaded with equally old thread for $3. at a yard sale, and I really enjoyed the 'look' of it. I actually got complements about my 'vintage display' on my thread rack. Fact of the matter was, I fully intended to use it, but it did look nice there.
Since I was a novice sewist, I figured if the thread was strong enough to make a bobbin without breaking, then it wouldn't be a problem if I used it on my early efforts. When I hemmed rags for practice, I used the wood-spool stuff. When I tried a new project in dollar-a-yard fabric, I again used the old thread. New techniques often got worked up and experimented on in thread older than my parents. And it worked up fabulously ! Many times, the sheen and appearance of the old stuff was a bonus, because it worked better than the brand-new thread, too.
So, while I'm sure there's lots of reasons *not* to use old thread, it may be worth a shot to try it out before throwing it out ! All else fails, the wood spools sure are pretty, empty or full - and our son steals 'em as soon as they empty for his various car and train playsets !