50 Shades Of Green - The Discolouration Reference & Discussion Thread

[Captain Antilles]

INTRODUCTION

Discussions about loose vintage figure variants apparently having 'unique' paint schemes / coloured materials (plastic & fabric) occurs regularily. Unfortunately due to the demand for 'variants', eBay appears increasingly flooded with these 'so called' rare and unique figures which can catch out the new collector. To be a 'true variant' the colour of the paint, plastic or material needs to be the same as it was when it left the factory.

Due to the age of our beloved toys these new 'variants' are in fact the result of degraded figures / accessories which show discolouration for example the common yellowing of white plastic.

This thread summarizes some facts about colour degradation and yellowing.  

It is our intention to aid future discussions about so called 'rare variants' which are in fact nothing more than the result of the degradation of the  materials used to produce these figures.

DISCOLOURATION

The different pigments used in the paints, plastics and fabrics applied to vintage figures have different degrees of sensitivity towards degradation by UV (ultra violet) light and chemical breakdown. Over time, some of the pigments can appear either less intense (fading), or changed in colour (degraded).

How can we explain these changes in colours? For example how can a brown pigment turn green for instance?

There are different theories which might all fit depending on the discussed pigment. Let's go through them briefly:  

#1: Chemical Breakdown

Some pigments within paints can change or lose colour through chemical breakdown - for instance oxidation or exposure to UV light.
This explains for instance why pink paints used for hands, face or neck sometimes become very pale or even appear white.
The varnish used to cover metalic paints on vacume metalised plastics is also prone to degradation, causing it to yellow. This can result  in the so called golden R2-D2 domes or golden Death Star Droids.    


#2: Green, Orange, Purple Theory

Some colours can be composed of different pigments, e.g. Green (yelow+blue pigments), Orange (red+yellow pigments) and Purple (red+blue pigments). Degradation can cause the relative amounts of the pigments to be changed, as one pigment degrades faster than the other.  

For example: Prune Face. If we assume that the green colour of the moulded plastic legs is composed of yellow and blue pigments, and that the yellow pigments have somehow degraded more over the course of time. We can then understand the two things which we actually see here: the green is shifted to blue (less yellow), and the colour is less intense (faded).

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•Orange (red + yellow) fades to yellow: Red fades away, yellow remains. Example: Boba Fett with yellow shoulder patches, wrist and knees (the blue plastic limbs have also faded).

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•Brown (red + yellow + blue) fades to green. Red fades away, yellow + blue = green remains. Examples : Chewbacca green limbs and Yoda green snake

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•Blue fades to light blue/grey. Example: Max Rebo with faded limbs.

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Now, how do we explain the mixed limbs Chewbacca below?

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The answer is that different pigments in the brown colour mixed through the plastic are expected to have a different sensitivity towards degradation, resulting in a colour shift during time (here brown to green as the red pigment decays). Assuming that the figure has the same light exposure during time, the extent to which a pigment in the brown plastic was prone to degradation is depended upon the direct chemical ''environment'' which can accelerate degradation reactions and therefore makes things worse. Think for instance about the concentration of neighboring plastifiers, or flame retardants (producing free radicals) within the plastic. Different batches of plastic might have slightly different compositions, and therefore the colour shift might progress at different rates.
In the case where a factory would mix up the limbs from two different batches (which might be common practice in the Kenner factories) you could thus end up with the mixed green/brown limbed Chewie as shown in the pic.


#3: Cyan, Magenta Yellow Theory.

The subtractive colour theory explains the observed colour differences even better. This theory uses Cyan, Magenta, Yellow rather than Red, Yellow, Blue.

- Ugnaught's cape: 'Neutral' coloured cloth dyed blue - magenta & cyan (1:1?). The cyan 'fades' leaving a magenta cape.

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- Dengar painted torso: Dark purple made from magenta, some cyan and some yellow (2:1:1?). This time the magenta fades leaving the paint green.

- Luke / Rebel Soldier & Commander / Bossk painted legs & feet: Brown made from magenta, yellow & some cyan (something like 2:2:1 or 1:2:1?). Magenta fades leaving green again.




TAKE HOME MESSAGES:
- No matter what colour theory (#1, #2, #3 or something else), the underlying mechanism - colour change of paint, plastic or fabric by degradation of different pigments - stays the same.  
- Also be aware that limbs and torsos are made from different plastics. The torso is usually made from a harder type of ABS plastic (acrylonitrile butadiene styrene), whereas the limbs are made from a softer PVC plastic (polyvinyl chloride). These two types of plastic may discolour differently in time. Sometimes you read in threads: "The limbs have a different colour compared to the torso, so it can't be degradation because you would expect the same colour change everywhere then!." After reading this thread, you will hopefully be better informed.

YELLOWING

Yellowing is something different than discolouration. It is caused by chemical oxidation reactions within the plastic (not the pigments within the plastic!), either spontaneously or initiated by visible/UV light or heat. It is likely that this process is accelerated by temperature fluctuations and humidity. To make a long story short, in the end you have more molecules in the plastic which absorb blue light giving the plastic a yellow appearance. The chemical reaction proceed further, meaning that in the end plastics can even turn pink.

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CAN THIS PROCESS  BE REVERSED?

In general: Degradation of pigments is caused by light and/or chemical reactions and can not be reversed, we are talking irreversible chemical reactions.

Warning: It has been shown that yellowing can be reversed by using strong oxidizing agents like hydrogenperoxide or bleach. Basically you destroy the newly formed molecules which absorb the blue light. So you end up with a bright white figure. However by doing so, the plastic is exposed to some aggressive oxidizing agents, thereby laying the seeds for (even more) yellowing in future. It has been demonstrated that this is likely to be a temporary 'fix' and the discolouration will return. We also don't know what the long term harmfull effects will be e.g. more brittle plastic. So we do not recommend using this method.

BIOTRANSFORMATION

Under the right conditions (warm temperature & high humidity) fungi/molds can use many organic materials (including plastics) as a food source.
Colonies of fungi can be observed as spots on Star Wars figures and give rise to a speckled appearance. Common colours include rusty brown, pink and green.

Fungi can be killed by bleach and UV light, but keep in mind that such treatment might also have a detrimental effect on the plastics/pigments.

Moreover fungi have spent a few billion years longer on this planet than us and have successfully developed spores which are more resistant to antifungal treatments. Spores serve to spread the fungi to other areas and start a new life there. In this way fungi could in principle infect neighbouring figures. We sincerely hope this remains theory and won't happen in real life collections, but o be sure it is recommended to store figures exhibiting mold spots away from the rest of ones collection. Below is an example of a childhood Snowtrooper affected by pinkish molds.  


Biotransformant: Jawa affected by fungi/molds.

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SOME DEFINITIONS: VARIANTS, TRANSFORMANTS & FACTORY ERRORS

VARIANT:

A figure that left the factory in its present appearance and which met the Quality Control standards at the time of production. A variant deviates from the "standard" figure.
The variation might refer to:
- paint application (Ben Kenobi with white or grey hair).
- COO (Taiwan, Hong Kong, 2 line, 3 line etc.)
- sculpt (Han Solo small and large head, Blue Snaggletooth, but also smaller differences mostly connected to the COO families).
- accessories (single and double telescoping light saber, vinyl and cloth cape Jawa cape).

Normally variants were produced in high numbers, but there can be exceptions when the QC standards were changed during production. This is probably the case for the Lili Ledy Removable Rocket Boba Fett with loose non sonic welded rocket, or Orange Hair Luke.



TRANSFORMANT:

This refers to a figure that got its present appearance after a visual change during time (green limbed Chewie, yellowed Stormtrooper, etc.).    
Consequently, a transformant did not leave the factory in its present appearance and is therefore NOT a variant.

Some transformants have an interesting visual appearance and are well established among collectors, e.g. purple smock Ugnaught, green limbed Chewie,... IMO these transformants have a place in collections, but just keep in mind they should not be considered true variants.

IMPORTANT: The appearance of a transformant figure might be traced back to a specific batch of factory-used materials (plastic, paint) in combination with a used mould, COO. Still that doesn’t make them true variants as they did not leave the factory that way.

- Example 1: Take the green limbs Chewie mentioned above. We believe he was found only with certain Hong Kong COOs. So probably the green limbs Chewie can be traced back to a factory which used batches of brown plastic with a (slightly) different composition in which the red pigment was more prone to degradation, giving rise to green limbs after 30 + years. Still this figure is a transformant not a true variant. Why? Because he did not leave the factory with green limbs thirty years ago.

- Example 2  The green neck Leia Bespin. With this figure the metals in the applied gold paint reacted chemically over the years resulting in a green neck. In this case the green neck can be linked directly to the used gold paint, so you might argue, this is a true variant. But it is not. Why? Because the green neck Leia never left the factory in her current condition thirty years ago, so this figure is a transformant too. If you would have a gold neck Leia in your present collection, it would of course be a different story, that figure would be a true variant, as she represents the Leia that the factory intended to produce in the 80s.



FACTORY ERRORS:

Figures that left the factory in their present appearance but which did not met the QC standards at the time of production, and instead accidently slipped through. For instance paint errors, Lili Ledy Removeable Rocket Boba Fett with loose, incorrectly unwelded rocket.
By nature factory errors are produced in very low numbers.

Like transformants, factory errors are NOT variants.  

EXAMPLES OF TRANSFORMANTS

Below you see the transformants which have been discussed in this thread. You can help by posting pics of your examples as well.

[Commander Clint]

Captian Antilles, Great article.

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[hellhippie]

what an amazing arcticle .. really clears some things up for sure

[ourchickenshack]

Great write up and very informative

Here's one of my favorites ...

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[poncho]

great article :-)

[Commander Clint]

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[Akial]

Thank you very much for this article. I want to contribute my most loved transfomant - the lavender rebel Soldier :

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[cantina_patron]

That's a great looking piece Dirk. Thank you for sharing it with us.
Have you ever seen any other examples?

[Commander Clint]

Dirk, that's a fantastic example.

[Akial]

You mean another Rebel Soldier like this? No never saw one like this or similiar before.

[Nico]

Great figure Dirk, awesome colour thanks for posting mate

[hellhippie]

WOW Dirk , super cool and lamely one of my favorite figures . I wish I could get one like that ..

I wonder what did that to him

[cantina_patron]

You mean another Rebel Soldier like this? No never saw one like this or similiar before.

That's the one Dirk. It's unusual to see the hard torso plastic turn the same colour as the soft limb plastic and the presence of an unaffected limb supports the idea that these colour changes can be the result of unstable pigments in the plastic (as well as environmental factors). The 'normal' leg was clearly from a different batch of plastic like the mixed limb Chewbacca in the article.

[Commander Clint]

It's unusual to see the hard torso plastic turn the same colour as the soft limb plastic and the presence of an unaffected limb supports the idea that these colour changes can be the result of unstable pigments in the plastic (as well as environmental factors). The 'normal' leg was clearly from a different batch of plastic like the mixed limb Chewbacca in the article.

Steve, your right. usually it's either the hard torso plastic or the softer limbs, but not usually both. That is unusual.

[Akial]

For me this Rebel Soldier is a mystery. As you all know the plastic of the body is different and much harder than that of the limbs. In this case the right leg and the body - both made exact the same Transformation while the left leg stayed in the original colour. Well I understand what Steve wrote in his article that these two legs are most likely from different material. But that the hard plastic torso and the softer leg are changeing in absolutely the same way ..... and in such an extrem way (from brown to lavendar) which I never saw anywhere else........ leaves me still confused

[Commander Clint]

Don't forget about cloth capes.  I pulled this picture from ebay a few years back, and the back ground was edited out.  Clearly shows the cape mid change.

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[cantina_patron]

That's another great example illustrating the process of degrading Clint. Hopefully collectors seeing this will think twice before paying over the odds for an alleged orange caped squid. They are a nice oddity, but not worth the money they go for these days.

[Commander Clint]

They are a nice oddity, but not worth the money that people are willing to pay for them.

[Commander Clint]

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[Commander Clint]

Another gem.

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[Commander Clint]

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[cantina_patron]

Nice additions Clint. With help from all of our members we can make this a very comprehensive guide / resource. So share your degraded figures guys.

[Commander Clint]

Thanks Steve, hopefully some of the members will start posting examples of what they have in their collections.

[hellhippie]

i sold all of mine , jeez i really wish i hadnt now

[Akial]

Thanks Steve, hopefully some of the members will start posting examples of what they have in their collections.

Hi Clint, asking for more examples of colour variations is just like calling my Name
Here we go

sunburned Imperial Commander

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green armor 4-lom, green snake Yoda, yellow snake Yoda

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green hips/ boots Rebel Soldier one painted and one molded legs.... and of course the famous lavender One ;-)

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IG 88 EYE's from dark red over orange to yellow

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My Squidhead Rainbow

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