Life expectancy for silk

[Fishnkilts]

I have been looking around for silk thread, and I found a few brands I will try when I need to order more. I have a few spools of Pearsall's silk left, so I'm not in too much of a hurry, but reading reviews on the other brands, YLI and Ephemera brands, I read somewhere that even spools of silk kept in cool dry areas will get weaker in time.

So my question is, how long is the life expectancy of spools of silk not used yet? I fear having to throw all my spools away because it'll be a big waste of money to order a lot of spools, especially if I don't use them up quick.

[Roadkill]

Probably depends how it is kept, I have silk sewing thread on wooden spools probably around 80+ years old that are still good for tying.

[Johnno]

I have some Pearsalls that I think had been stored in the sun at some point in its past. It’s very brittle. However when I’ve peeled off a couple of yards to the stuff that wasn’t exposed, it’s good as gold.

[Theroe]

I have some that’s great and some that’s basically falling apart. As with any other organic material it’s all in how it’s been stored over the years......