Resin Yellowing: Causes and Protections

Clothing (and things like curtains) do not block all UV exposure, they only reduce it. The thicker the layering of cloth (more layers and/or heavier fabrics), the more blocking that occurs, and it IS possible to block pretty much all exposure with cloth, but it takes many layers. The simple explanation for this is that cloth is woven (or knitted, etc), not solid, and UV radiation can still pass through the holes in the weave. The thinner fabrics and fewer layers that tend to be used in doll clothing (since thick fabrics/many layers are too bulky to really work with dolls) will certainly reduce UV exposure, but not totally negate it.

 

I've been sanding Carousel recently in preparation for dyeing, and noticed that he has yellowed quite a bit. He's a bit over a year old now, and I haven't taken a lot ofp recaution about keeping him out of the sun and such because I really don't mind the yellowing. But earlier this year I got to stand him next to a newer Sabik who'd been more protected, I believe, and the difference was really obvious. The other sabik was a soft, more pinky nude color, while Carousel was deffinately more yellow-gold. Which makes me just happy because I like him more yellow.

However, in sanding him, the sanded parts returned to their original color without too much effort. These parts will be dyed so I'm not too worried about it, but if I decide to sand his seams, it'll be interesting to see if the color difference mellows over time. I've heard it does.

 

HMMM my second had doll was posted as never been yellowed, however, it is obvious that she is yellow in comparison to her parents :P it is nobody's fault really, each doll yellows differently... i have sanded mine to the core to expose the inner resin, which is creamy ^^

 

I am a doll owner that is insanely worried about yellowing/sun damage to my dolls. However, I dont 'play' with them as most people do, so ease of access/display is not a factor for me. They are taken out 4 or 5 times a year to show to friends and placed back in their boxes, which are kept in their shippers, which is placed under the sofa in our parlor.

Personally, I think any exposure to sunlight, regardless of 'protection' in the resin or semisheer coverings, still exposes to doll to some UV rays (though exposure might be radically reduced, its still there). If you are truly concerned with sun damage to your dolls, I think the absoloute safest thing is to keep them boxed up.

Though, of course, you end up like me and hardly ever see your dolls

 

You face the same dilemma that the owners of collector cars do. Do you enjoy your doll (car), take it out and play with it (drive it), not worry about anything but extremes of sunlight (weather) and get as much out of your dolly dollar (car dollar) as you can by having fun (fun) and not worry about yellowing (depreciation) or accidents and damage (accidents and damage)?

Or do you worry about your investment, and lock it up where nothing can happen to it?

Only you can make that choice. For me, it's not a choice. We won't have a doll (car) that is a cabinet baby (trailer queen).

 

You would need UV protected glass, such as the kind that is used in libraries with a lot of funding, which is usually quite expensive. Even with UV protected glass there will still be some exposure that can lead to yellowing. No glass is 100% effective at blocking sunlight.

Knitted and lighter fabrics will let some sunlight through and knits definitely could lead to some striping. It hasn't happened to me but is definitely within the realm of possibility. However, white or light fabric is definitely a good option for protecting against indirect sunlight as AmyAngel said. Darker fabrics will protect against the sun better but also contribute to heating up your doll. This can cause issues as well. That might not be a problem for some but it might be an issue for owners, such as myself, in areas with lots of sun and heat.

I'd say rather than depending on some kind of cloth covering to protect them you should make sure that wherever you are leaving them for extended periods of time is out of the light. It's usually the best way to prevent sun damage.

 

I agree with Victoria Victrix - and remember, if it's yellowing you're worried about, that will happen whether your doll ever sees the sun or not! It'll be somewhat slower if you keep your dolls boxed up all the time, but they'll still change and age over time, it's just the nature of resin.

There's absolutely nothing wrong with keeping them boxed up all the time, if that's how you prefer to keep them. But don't feel like you have to keep them boxed up if you'd be happier keeping them out all the time! I personally want mine out and visible (though kept covered when I'm not around to see them), and I don't even HAVE boxes for most of them. But everyone collects differently!

 

I have a question about yellowing. We all know direct natural sunlight causes fast yellowing. However, what about artifical light designed to be natural looking like Ott Lights? They have a more natural light spectrum, but do they cause yellowing at the same speed as natural light? It's a bit of a concern for me because that is my desk lamp and I use this desk for EVERYTHING, so the lamp is often on and my dolls are exposed to it. Anyone know anything about this?

 

*feels sheepish about asking a newbie question*
If I keep my doll in a cupboard in my room when not playing with her or photographing her, how long will it take her to yellow? And also,what does the yellowing actually look like? Is it like, properly yellow, or does it just look a bit old and antique-y?

 

ive never seen a doll look really banana yellow or anything, its more of an antique feel. What i think happens is the uv dulls the red pigments in the resin, leaving the more creamy gold colors. Alot of doll owners are worried about this but ive never seen a case that makes me cringe enough to hide my dollies in the dark all the time. As far as how long? no one can say that.. it depends on the company, the particular resin batch, how much time you expose her to light when photographing, etc. I dont think its possible to completely stop a doll from yellowing at all because there are other factors that cause it besides light (or so ive heard) that yellowing is just a natural process for these dolls and most owners dont even notice.

 

I was wondering about this all myself with my twins and there were some things that just didn't quite make sense. (At least, that I could work out.)

I've read that sunlight is supposed to cause a doll to 'yellow' or age more swiftly than not, (or the UV from it, rather,) anyway and couldn't help but compare my two boys (both DOT Sha's.) True, I got Orion in Feb and then Gabriel a few months later, but the difference between the two was extremely obvious, even though neither had really ever been exposed to sunlight.

They generally stay in their boxes when I'm not home and when I am, it's always too late so no need to worry about sunlight. But in saying that, I'm almost completely positive that Orion wasn't quite as pinkish as Gabriel to begin with which brings me to what I was actually trying to say; is it possible that resin discolouration may vary with each batch? Or Season? Reading through something on the procedure to make dolls, I know humidity comes into play-could this possibly matter?

I read someone elses post, where they state that it didn't seem to but... meh. Just musing out loud hoping someone has some insight?

Could possibly just be the weird seasons we get here, Or our killer UV rays

 

I bought blackout curtains for my office/doll room yesterday. They are meant for home theater rooms and they block out ALL of the outside light very effectively. They are made of suede fabric backed with another opaque fabric. They were no more expensive than regular floor length curtains, and they are pretty widely available, given the growing popularity of home theaters.

I plan on keeping the drapes closed most of the time so that I can display my dolls with less worry of yellowing (esp. my french resin guy) and I'll cover the dolls up if I need to open the drapes to get some light. I'm really happy because I've kept my guys in boxes until now, which takes some of the enjoyment out of having them. Now I feel like I can have them out without too much worry.

And a bonus: since the drapes are light-opaque they should make the room a lot less hot in the summer (southern exposure).

 

I'm not sure if any of these has been asked. It's a concern of mine, as is preventing dye transfer, but that's for another time. I've searched all over the place (not just DoA) and couldn't find answers to these:

1) Does yellowing eventually happen to all dolls?

2) Do certain doll skin tones (white, natural, tan) yellow more, or faster than others? Do any not yellow at all?

3) Are certain companies known for having dolls that yellow more or faster than others?

4) How long will it take resin to yellow?

5) What can you do to a new doll (fresh out of the box) to either stop, or slow down possible yellowing? What works best?

Well, that's it, I think. I hope they don't delete this, but if they lock it, I hope they redirect me to somewhere where I can get some answers. It is a concern of mine.

 

1) Does yellowing eventually happen to all dolls?

Yes :> All resin yellows, no matter how you protect it

2) Do certain doll skin tones (white, natural, tan) yellow more, or faster than others? Do any not yellow at all?

Tans would yellow slower, but some tans go green after a day in the sun o-o ( IH) White is more prone to yellow faster. To be short: The more red pigment is in the resin the longer it will take for it to go yellow. White got very little so it goes yellow rather than loosing the redness first.
I'm currently yellowing a very pink doll..He's been in bits by the window in the sun for like a week...nothing happened -_-
3) Are certain companies known for having dolls that yellow more or faster than others?
Luts go yellow fast as far as i know.

4) How long will it take resin to yellow?
Depends on the resin and the company, Heat, Sun exposure etc

5) What can you do to a new doll (fresh out of the box) to either stop, or slow down possible yellowing? What works best?

Uv-cut MSC should slow it down but it cant protect it against heat. Keeping your doll in the box might not work either. There is been cases of people keeping dolls in boxes for ages but the getting them out all yellowed.
Just enjoy your doll , few years down the track, extreme yellowing can be reversed by some peroxide and soda solution. It wont return the red pigment to the skin but it will lighten it. So even the pinkiest resing can be turned almost white if needed.
Keep your doll in shaded area away from heat and it will be fine ^^

 

And lo...there was a search tool, and it was good for it magically produced the answers to questions already asked in large quantities and allowed us to look things up in mere seconds.

Resin Yellowing: Causes and Prevention
Lightening French Resin Yellowing
Greening in Tan Dolls

 

Well, this is what I get for not searching the forums long and hard enough. I did search both DoA and the internet -- and the minute I post this thread I discover, as you said "lo" and behold, most of my questions were asked somewhere else. A bummer for me, but I still got my answers anywho.

 

To help you out:

http://thedermblog.com/2009/06/21/fluorescent-light-bulbs-and-uv-exposure/

 

Flourescent light bulbs?

I have cool white flourescent light bulbs in my room, there really is no place to hide unless I shut my doll in a cupboard lol, should I be concerned about just light bulbs? They're only 9 Watts, 120V.

Just asking lol; since so many factors can contribute. I really want to keep my WS boy this way as long as possible~!

 

Hi draa XD Congrats on receiving your boy! Funny to see this post after popping on for 2 seconds haha. Yellowing is largely contributed to sunlight and UV degradation, but it is also inevitable via oxidation. Short of putting your doll in a space time vacuum, yellowing will occur.

I realllly doubt that resins are volatile enough to be affected by light bulb light rays. The frequency and strength of the output of rays from bulbs is incredibly minimal compared to just being in filtered sunlight even.

If you really wish to keep your doll as white as possible, I just recommend putting him in a dark protected place [it hurts to see them shut away, I know!] when you're not playing with him. Even putting him back in his box or your cupboard would slow the yellowing rates [minimally, but every little bit counts!].

If you were REAAAAAAALLLLY intensely keen, I'd put some sort of plastic wrapping when he's not in use, as plastics effectively slow the movement of oxygen better than just a box. But that's pretty hardcore. :}

 

I'm sure there are certain lightbulbs out there that would speed up the process of yellowing but it's honestly so minimal it's not worth worrying about. Too much direct sunlight exposure is the only sure first quick tell-able way to yellow your doll, otherwise just time. Eventually it will happen, just keep away from direct sunlight and when it finally happens noticably enough that it bothers you, if you can part with the current faceup, clean off the faceup, unstring the doll, get yourself some basic oxi-clean (no additives) and follow the directions on the back of the can or bucket and soak the doll... then repeat if it's not light enough after the first time. Does serious wonders for older dolls, especially white skin.

 

sunlight is the main cause of resin yellowing, but don't forget oxygen!!! when it is in contact with air, the probability is high it turns yellow TT___TT

 

Has anyone noticed yellowing in Elfdolls? I have a Mir and a Hazy who are both kept on a shelf out of direct sunlight. I have not noticed any yellowing; but do have plans to eventually put them into a basement den/tv room.

I have an resin cart that I keep my art supplies in, which is about 20 years old. The cart has been in a variety of light situations and has gone from snow white to a very ugly yellow.

I sure hope that never happens to my dolls.

Hugo

 

I am curious regards to what kind of factors affect urethane yellowing.

The factors I came up with are mainly climate, company, treatment (cf. kept in box, went outside for a few times...) and type of resin (cf. french).

So it will be fabulous if you could provide detailed cases of yours!!

Mods-I looked for similar thread but couldn't find one...though I do remeber seeing it somewhere about a year ago.Sorry. So may as well regard this thread as number 2?

 

I agree with you on several of your points! I think that if your doll spends a lot of time out in the sun, it will yellow much faster compared to one that has been kept in its box or a very dark place.

I know company also has a big effect on it.. I have two Blueblood dolls, and their resin is not like other dolls'. They are both made out of a resin that is safe for the environment, but it really reminds me of french resin--it has that same translucent glow. Because of this, their tone is more yellow. I've had them both for over a year now, and I can't notice any change in the resin (no further yellowing), but I'm sure that their skin tones will become creamier over time.

 

The UV rays from the sun is the main problem but florescent light emits uv rays also also i read that its a natural process for resin the uv and temperarure n other factors only speeds it up. In our country aged dolls tend to hav a lite tan color tho i dunno why instead of getting yellow they turn lite tan and theres a normal skin Luke here that turns whiter over time instead of yellow. Hmmmm this is really intriguiing am gonna research some more n post the results here

 

there are some popular reasons that makes dolls come to yellow, touch air, high temperature, sunshine, so if we want them yellow slower, we need to put the dolls in box.
I have 2 same doll, they have the same white skin color, one is made earlier about half a year, I bought him from another peaple, at that time he's one year old, but not yellow, I very love him, so I always put him on my bed all the day, the sunshine can't reach him directly, but a month's later, I found he's yellowed very much, then I put him in the box with the another new doll, everyday put them outside no more than one hour, until now is a nother half year, the second doll is still white, so air affect urethane yellowing very quickly.

 

poochiness, I have not known that BBD has unique resin! Now I wonder how differently they yellow. As you said, one year dolls don't really show signficant sign of yellowing. I will need to check upon older ones~

crownedprince, you are sooo lucky. Tanning sounds a lot more charming than yellowing. I have never even thought about dolls naturally "tanning." Please do post more about it!!

mingyan, only a month affected that much just by keeping him in room environment? I have Kakeru stadning right by me now for weeks but I haven't noticed yellowing yet. Perhaps because of different company's resin?

 

I'm having a hard time understanding what makes this a debate . . .

There are indeed quite a few threads in Painting, Customizing, and Esthetics about the causes of yellowing, such as these two:
http://www.denofangels.com/forums/showthread.php?3436-Resin-Yellowing-Causes-and-Protections
http://www.denofangels.com/forums/showthread.php?88212-French-Resin-and-Yellowing

If you do a search in Painting, Customizing, and Esthetics, you will find many more informative threads about yellowing.

 

Thank you so much! I did not expect to see such thread in Customize category, so I did not look into it there.
I just assumed that it can't go to newbieland and put it here.

 

hey,dear.
I think that the problem of yellowing, in essence is the oxidation, but light, humidity, temperature, and air also cause yellowing.
Yellowing of the process is the process of oxidation, and this process is not reversible. Unless the dark vacuum low-temperature storage, otherwise, the yellowing can not be avoided.but the materials may another problem.I have some different doll from different company,At the same time, they have different degree of yellowing.
what's more,I think we should beware of the sun beating on your unprotected dolls.and some protective measures are also very necessary.

 

I'm curious to know how boxing your doll up is different than putting them in the storage bag? Some companies sell you the doll in the bag, so you don't even get a box, and most now are sending them in pillows. While it's all for the safety of shipping the doll, for a storage when you're not playing with/enjoying your doll, is it ok to store them in a bag?

I have a box for my MSD but I was considering getting a bag since it's easier to carry around . . . But should I keep the box for the storage time of the doll and only leave him in the bag for shorter periods?
Yes get bag for storage and moving purposes, or just have the bag for moving only. . .?

How would this then effect the storage of dolls that only come in bags?

 

yes, perhaps different companys dolls' quantity is really diffirent , the 2 dolls I own was made by Angell-Studio, the kind of skin is a liitle transparent than their white skin, and this transparent skin, we always say snow skin, make dolls looks very reiki if compare with the solid ones, but relatively, it's famous for yellow quickly!

 

Different companies' resins are definitely different!! Formulated differently, different colors, different translucencies. That and where they're stored/ how much ambient light they're exposed to are all factors. In general I find the more translucent the resin, the more readily it yellows. If where you keep your dolls is bright your dolls will yellow faster/sooner. Sealer yellows on its own, I've cleaned sealer off dolls that ends up being quite brownish on the white washcloth I use. Of course dust and dinginess from handling can make them look yellower than they are too, so a bath now and then can help.

 

Stumbed through the search feature and couldn't find an answer but I apologize if this has been rehashed several times already: I have a MNF head and it is beginning to yellow. I don't keep her in direct sunlight, she lives in a room that is completely dark 95% of the year. But her face itself is beginning to turn. Her face and her head cap are just one shade different. She is on a Souldoll body so the difference is subtle but I can see it if I study her. She has a face-up but I want to try and reverse/stunt the yellowing on her face. What can be done? Is there anything?

 

Tbh, it depends on what's yellowed, the resin, or the sealant on the faceup. It's entirely likely that if the faceup was done with something like Testors (hilariously prone to yellowing), or is just old, then taking it off may also remove the yellow tint too. Time, handling and the atmosphere you live in take their toll on paint and sealants just as they do resin, but either way, if it's something that concerns you, your first step will very definately be to remove the paint and see what state the actual resin beneath is in.

 

I'm trying to find info of how long it takes for a doll to become yellow after sun expose, how many hours do my doll have left before it starts to turn into a yellow shade
I try to keep my doll away from the sun, but pictures inside often become to dark

 

It takes many hours of direct exposure to yellow most resins. French resin yellows faster. Read the thread for info about it and how to prevent it. Even if it does happen it's often simply a mellowing of skin tone instead of a turning buttery, and can be fixed by sanding or blushing.

 

Your doll will likely be fine with some sun exposure.

Even the most radical shifts in unstable color take more than a few minutes exposure to sun, and those are quite rare--deeply colored resins or 'french' resin, which starts off transparent & allows light to penetrate it more easily than more opaque resins.

Most dolls' yellowing is a color change like ivory, not a sudden resemblance to a lemon.

 

It's a matter of months or years more than hours. Dolls yellow gradually and the process takes place over time. I leave most of my dolls out in my living room and they get a pretty decent amount of indirect sun exposure and some of them I have had for a couple of years still have not started to yellow. So don't worry about taking them outside for pictures for a few hours. They don't yellow that fast!

 

Has anyone wondered if there is a significant difference in yellowing caused by oxidation at sea level and at higher altitudes?

I know all air is ~21% oxygen but with the lessening pressure as your altitude increases there are fewer molecules present in air, therefore less oxygen. Just a random thought.

 

Hi guys,

Sorry if i posted this on a wrong section... I was just wondering how do the dolls get some yellowing on their skins!? I'm pretty curious, and just wanna know how and how to avoid them... Hope you can share some infos about this, so that i can take good care of my doll when i got it here. Thanks much!

 

most dolls will yellow a little over time but its usually made worse and sped up by direct, strong sunlight and heat

keeping the doll out of strong sunlight or extreme heat are the best ways to avoid unnecessary yellowing

you can also get some UV resistant sealants and some doll companies have UV resistant resin

 

I'm not knowing alot myself, but I heard resins reacts with oxygen, oxidise and become yellow. And UV and heat speeds up the reaction.
So if you want to make the reaction least-active as possible, cover him/her unless you are not handling the doll And put in cool places

 

Sorry for being a such a Silly Guy! That does mean an extra fee or extra free service for the company!?

I see... That means, no outdoor photos for my doll then

 

There are so many threads on this, you'll find them all by using the search feature. But yellowing happens, there's no way to stop it but you can lessen it by being sun-safe!

 

Outdoor photo shoots are fine - you'll find that many people do them It's just probably best that you don't plonk your doll down in the middle of the afternoon under direct sunlight for the photos. The best times of day for outdoor photos are early morning or late afternoon - you'll find the light to be better then, too.

As for the uv resistant resin, for the companies that do such things, the cost is already part of what you pay for the doll. And uv resistant sealants (like msc flat uv cut) are no more or less expensive to buy than other sealants for your doll.

Good luck and have fun with your dolly ^_^

 

I guess... I might schedule the perfect setting to avoid yellowing huh!?

Wow! Those are great tips! Thanks kirika-senpai! I will check that thread right now to know more... I don't have my dollie just yet, i just want to learn more about it, so that when the time that he arrives... I know how to take care of him well.

 

Yup, just make sure to keep the doll out of direct sun in storing, it should be alright for photoshoots though. I keep my dollie boy in my bed tucked in of a day (in the corner of my bed, even with the window open no direct light falls on him).

 

It's a chemical reaction, and like all chemical reactions there are methods which increase the speed of the reaction.

Sunlight (UV light) increases the breakdown of certain chemicals into their proponent parts, and resin is an unstable plastic. Exposing it to sunlight will break some of the resin's chemical bonds which will then react with the oxygen present in the air and create a slightly more stable compound (which has a yellow colour) So the chemical composition of the resin is changing at the level where it can interact with oxygen (the surface). Resin is also porus, which means that air can get to lower levels in the structure as well, which will mean that they also react.

It's similar to how if you leave a bottle of hair bleach in the light, it becomes less effective, because the Hydrogen Peroxide breaks down into water and oxygen when exposed to UV light. Only this time, the resin is taking the oxygen and using it to form different chemical bonds.

Heat speeds up the process of oxidation because there is more energy present for the reaction to use.

Certain environmental factors will also affect the process, but they're minor. The two big ones to worry about are heat and UV light.

You can use some chemicals to lessen yellowing - Bicarbonate Soda is one - the carbon will leech out some of the oxygen (creating carbon dioxide) and the resin will revert to it's original chemical compound. However, too much BCS or exposing the resin to the BCS for too long causes different chemical reactions to occur within the resin which can't be repaired.

A light sanding to remove any yellowing will remove the top few layers of the changed compound. If you then seal this with a UV-cut sealant, it will lessen the speed at which the yellowing will occur again, but it will still occur.

Apologies if some of the science in this is wrong - I'm not a scientist by trade, but I do find chemistry interesting.

 

Even if your dolls do get yellow over time, it's not really a problem. Some people actually like the look of yellowed dolls, myself included. And even if they do, there's a thread on how to lighten resin.

Just take care to keep your dolls out of direct sunlight and heat as everyone else said and there shouldn't be a problem really. C: And if you do, there's always that thread and forum.

 

I don't know if there are a thread about this already, I could not find one, but I don't know. If there is, please tell me.

I have some questions about yellowing.

When does it normally start to happen?
Does it totally ruin the doll?
Can you prevent it?

And anything else you can tell me about yellowing of dolls in general.

Thank you. =)

 

Hi I haven't really noticed a lot of yellowing on my dolls but it normally starts to happen if the doll is kept under too much light and sun exposure. They're all going to yellow up some day but I don't think it's really bad, it doesn't look that bad as it sounds and it shows the amount of time you had with your doll.
so you can prevent it by not putting your doll right under bright light. The resin will just look more yellow that's all. It's not bad in my opinion. If your doll is made out of French resin I think they yellow more quicker.

 

http://www.denofangels.com/forums/showthread.php?405992-Resin-yellowing-Paranoia!

I found the thread c:

 

Hi Lilja, and welcome to the hobby! You can probably find most of the answers you're looking for by searching in the Customization section of the forum or possibly asking in the NewbieLand section.

To answer some of your concerns - Yellowing/mellowing is more of an unavoidable, constant process, and for most dolls, is very gradual. Many owners don't even notice it until they put their doll next to a newer doll from the same company. The pigments in the resin break down over time, especially the red/pink tones. It can be accelerated by over-exposure to UV light and heat. UV protectant sealants can slow it, and sanding and baking soda peroxide baths can minimize it.

A doll that is yellowed unevenly may be less aesthetically pleasing, but it isn't really damage like a broken finger.

 

My Xavier will be turning six this year and he's a beauty white so he started off a creamy color. He's yellowed and gone slightly green so gradually that I've accepted it as part of him. It was only when he was around a brand new beauty white did I notice any difference and I love him too much to care.

 

An old thread as I see. Anyway I'll add a small suggestion: beware of close contact with paper. Paper have it's own acid level and tend to build it up with age. So if acid from human skin causes yellowing than acid from paper will do too.

 

Hey guys, so I got my first minifee not too long ago and am feeling some what concerned about yellowing. I am fairly new to the hobby (over 1 year so far) and have never really owned a doll long enough to see the effect of yellowing resin/vinyl. So in essence my question is - how easy is it for dolls to yellow, and do you have any tips to avoid this (other than the obvious one of keeping her in the dark at all times).


Thanks in advance!

 

Well, even if you keep the dolls in the dark they will yellow over time - keeping them in the dark only slows it down but doesn't prevent it from happening. That said, all my dolls that I have have yellowed pretty nicely. They're all on the ivory side of the spectrum.

My Fairyland Marcia that I bought from a friend is less peachy, for example, than the newer Fairyland boy I bought that's a couple of years younger. Still a nice colour, though. My oldest doll I got at home is one from 2003 and he's got a really nice ivory tone now. The only doll that's ever yellowed/faded in a patchy way is my Iplehouse boy and I got him before they came up with the newer UV protect resin (is that what it's called?). The newer PID Iplehouse doll that I got two years ago so far doesn't show any obvious signs of yellowing. And I have all my dolls out in the open where they're getting lots of light (no direct sunlight, though).

 

I hope my minifee yellows nicely over time then! I try my hardest to keep her out of sunlight, so hopefully that will cause her to yellow evenly. Thanks for the reply by the way.

 

I've got a couple of old, old LittleFees (from the pre-release event, so honestly about as old as they can get), and a Pukipuki who's even older than them; they all look fine, and the only real issue with matching on newer ones is that FairyLand suddenly shifted to a more pinky resin formula (the match between parts only a few months old was off, but the match between those parts and the older dolls is lovely).

I do know they've had some minor surface yellowing; I'm in the middle of a large, slow mod on two of them, and there's a slight color change each time I do some sanding or carving away at parts of the doll. There seems to be a "stable" point, though, as these have mellowed back to match after some time, and it remains a very nice, pleasing color.

I don't keep my dolls in the dark (they sit in my bedroom, on open shelves--no covers, no drapes, and I have a cat so the window's open). They're out of the line where the sun falls in the afternoon, but other than that I don't take any particular precautions with them, and my oldest dolls are still quite nicely colored. The only yellowing I've really encountered was in a secondhand doll who had rather bad, uneven yellowing--I can only guess he was left dressed in the same clothes for a longer period of time, with one side facing the sun, based on the pattern of yellowing as I cleaned him up. The only other doll I have that seemed "yellowed" turned out to just be a little dirty from age, and after a quick scrub is a lovely pink again, so I'm going to continue to not be too concerned with interior lighting. (Do note that CFL bulbs can produce a lot of UV light, though, and I've been transitioning away from them into LEDs; as I recall the dolls were generally in areas where I was using tungsten bulbs and went through only a brief period of CFLs, and I can't say if those bulbs have any effect.)