Resin Comparison (Any) aged grey resin

Well, I have a bit of insight into this, as I have a lovely 2008 DoD Delphine in grey who has definitely yellowed. I took some pics of her next to my grey Soom Crow from 2014, as well as a hand from my 2023 DF-H girl in grey. Now, none of them were ever meant to match each other, but here's a pic:



and a closeup:

Spoiler

I intentionally didn't edit this at all, and for reference the background and the top of her wig are pure white. My Delphine is second hand, but I've known her her whole life and know she was well loved and went out and about, unlike my Crow who has all but lived in a box in a dark room. Even so I can see he has some yellowing as well. I'd say their resin has yellowed, not blued, and with Delphine in certain lights she almost has a green cast to her as well.

If you'd like another other comparison shots regarding this, let me know.

 

@lutke I think you may confuse yellowing with fading. These are two different things, although they can happen simultaneously.

Yellowing happens because the polyurethane oxidizes.
The oxide is usually yellow-ish, but may have an amber or green tint to it as well. In grey dolls, this can make the doll look green-ish or brown, rather than true grey, but it's very rarely a drastic change. I think the image posted by Akai Okami is a good example of this and is probably quite representative of what to expect under normal circumstances.

This is different from fading, that happens because the pigments break down.

 

Pipes cube on the right from 2012 and Soom Cheshire from 2015

 

I’ve found, as with other resins, that how much it changes varies from company to company. In the past I had one soften nicely to a warm grey and another took on a more unpleasant greeny/yellow edge very quickly. I don’t have those particular dolls anymore so cannot show photos unfortunately. I think in both of those cases their may have been other colours present in those supposed ‘greys’.
My current grey dolls are recent acquisitions (Coral Reef head and DZ) and haven’t left their boxes other than initial checks, they shouldn’t have changed noticeably I hope.