I use old thread if it passes the snap test. I have used thread on old wooden spools as well as thread on plastic spools. I haven't noticed any more lint with the vintage thread than what I see in my bobbin area after using other cotton threads. Thread can dry rot or get light struck and it can also mildew. In the case of mildewed thread, you'll smell it. I throw that out. In the case of dry rot or light struck- I often find that the top layers of thread on the spool don't pass the snap test, but there is often good, useable thread underneath the top layer. That said, I use the vintage threads in art quilts, rather than in quilts that will be used and washed often.

Some of the thread I've used has been on spools that I guesstimate to be in the range of 80 to 100 years old. Just depends on how it was stored and quality to begin with.

Rob

Thanks for all the info......I appreciate it!
Have a great week all!

Snap test does it for me. I have thread I have had for 50 years and it is still good. I keep my thread in a spool chest so it isn’t light damaged. I love my old wooden spools.

I've never used old thread although I've bought some for the pretty wooden spools. I have them in an apothecary jar.
I don't think I've ever used them so I can't say anything about that.

Someone just "passed along" a big bag of old cones of thread to me. They are dirty on the outside but I planned to unwind that part and use the clean inside thread if it passes the snap test.

She also gave me a bucket full of white fine crochet cotton, like used for making bedspreads and tablecloths... or I suppose tatting. Have no idea what to do with that.

I use my own old threads with no problems.

I use old thread for basting.

OK, this may scandalize some of you. but here it is. I had some cones of serger thread that got dirty. I dusted them off, and used them just as they were. Yes, the tension discs in my serger may get dirty from using it, but it sits around without a cover and has done for years, with no ill effects noticed. Granted its a Bernette 43D and fairly ancient, but it still works. I figure that any serging I do isn't decorative, it's either inside a seam or on the edge of a rag or chore towel that's only going to be used for icky things I don't want to use a nice towel on. Also, hey! It's going to get washed when I wash the thing I used it on, so it will be clean then!

Incidentally, the serger didn't even seem to notice at all.

I also do this; however, I also purchase empty wooden spools for display or crafts.

I often tell students first learning to sew that if they were given their grandmother's stuff, the machine is probably great (just get it serviced) but the thread should probably be thrown out. 100% cotton thread can be a problem when it gets very old and especially if stored in the attic or garage for years. Poly covered will outlast the cockroaches! The bigger question is do you want to risk all that work for the cost of a spool of new thread?