Ultra violet degradation?

[JDR]

It is very common knowledge that ultraviolet light (sunlight) will degrade the intensity and hue of dyes.  This is particularly noticeable in clothing.  Since inks also use dyes for their color(s), I wonder if the same is true?  If I leave ink, stored in a clear bottle on my desk and it is subjected to sunshine for several hours a day, will the color and/or the vibrancy of the ink suffer?  Should inks be stored in the dark?  Are some inks more susceptible to this than others?

[I-am-not-really-here]

Assuming your desk is indoors, what type of glass is in the window that the sun is coming through?   Is the sunlight direct or indirect?  Another assumption: you do not have curtains or shades that can be closed at your discretion.

[txomsy]

Basically, it all boils down to reading the reviews about fade resistance in the Net and on FPN.

 

Some inks are UV-resistant, some aren't. Just like many other pigments. So, if you want to know for a given ink, simply read the reviews.

 

That is to answer UV-resistance.

 

Please, do keep in mind that sunlight may act in other ways: warmth and IR can also induce other chemical reactions, whether in the pigment or in additives. Again, that is also ink-dependent.

 

Which is to say, knowing it exists, why would anybody in a healthy mind leave any potentially sensitive product in a potentially damaging environment willingly? Just keep the bottle in its original box, or in a drawer, or in a shadow/fresh/dry environment (think of it like a good wine, only much more expensive), or in an UV filtering bottle or behind a UV filtering shield. Plenty of options to keep your goods safe.

 

Added: that's assuming you are going to keep it for long enough that the ink will fade. If you are using it at a reasonable pace, most likely the bottle will be empty before you notice any degradation.

[JDR]

Thanks for the response.  My windows are very new and do have UV filtering, I am just curious.  With your answers it does raise the question about why a manufacturer goes to the trouble make a unique or beautiful bottle - like some of the newer Diamine bottles and the Iroshizuku bottles if they are better kept in the box or a drawer.

[I-am-not-really-here]

4 minutes ago, JDR said:

why a manufacturer goes to the trouble make a unique or beautiful bottle - like some of the newer Diamine bottles and the Iroshizuku bottles if they are better kept in the box or a drawer.

Marketing, for one.  A fancy glass bottle can be perceived as an objet d'art to be displayed.  But to @txomsy's point, you are supposed to be using the ink in a timely manner.  Otherwise offload the ink to a plain storage bottle kept in a drawer.

[txomsy]

Because if it is not directly exposed to sunlight and it is to be used, one will run out of ink before it ever gets spoiled. Plus, if the ink is fade resistant, then it is not that much of a problem.

[InesF]

Be aware that light from a fluorescent tube or from some of the halogen bulbs can contain some unfavorable light spectral bands that may interact with dyes or other components of the ink. It often is, but it doesn't need to be UV light which fades a dye. The dyes have colour because they absorb light of a specific wavelength. Each photon absorbed transfers energy to the substance. And as @txomsy already mentioned, some of the dyes may chemically react, others not.

 

However, don't be afraid too much. To bleach a fountain pen ink in its bottle when kept indoors will require many months, most probably years to change the colour enough to be noticed.

 

If you have too many inks accumulated, better keep them in a drawer or in a box or in a case ... 

[Bo Bo Olson]

Wheeee!!!

OP was talking about sunlight, not my 20 or more year old Ultra Violet ink. Whoooops!!!

Rotring brilliant ultramarine.

In the third and last place I hide ink.

Below the insert, is bracelet cases with other fountain pens...like my brown Bakelite case with my Virginia Woolf in it.

[Lithium466]

Rotring brilliant Ultramarine - I used to love that ink...now I wonder what would work best as modern equivalent. Maybe Diamine Sapphire?

[arcfide]

The short answer is that light is almost certainly a danger to the vast majority of fountain pen inks. However, if you commit to using a bottle of ink up, and you keep the bottle indoors and generally away from direct, intense light and heat, you can probably, as others have noted, use up that ink in a timely fashion. And even if not, there are plenty of places where you can place a bottle of ink and still display it without exposing it much to the elements. 

 

And even if you don't show off the bottle all the time, just enjoying it when you pull it out is sometimes enough. 🙂

[txomsy]

Agreed. Specially when one has so many bottles.

[LizEF]

On 3/2/2024 at 9:10 AM, JDR said:

subjected to sunshine for several hours a day

Personally, I'd be at least as worried about biological (e.g. mold) growth as about fading.

[InesF]

On 3/3/2024 at 2:36 PM, Bo Bo Olson said:

Ahhh! The Virginia Woolf! +1 👍

Such an adorable fountain pen!