Can someone explain how an ink would turn lighter in colour in a pen that is capped and unused for several hours?

[A Smug Dill]

I'm at a complete loss trying to figure out why this is happening.

 

The nib unit for my Santini Italia Calypso Mother-of-Pearl pen, which houses a rhodium-plated 18K gold nib and an ebonite feed supporting it, has just been returned to me from Italy after repair.

 

I bought a bottle of Waterman Mysterious Blue ink from a local department store a couple of weeks ago, while the nib was still away. After flushing and drying the nib unit, I decided to fill the Calypso pen with this ‘safe’ ink first, to test how the repaired nib writes. The first few pages of writing samples were sufficiently ‘wet’ on the page, that the ink marks exhibited sheen on Rhodia DotPad 80g/m² paper. I reported back to Santini that the nib is all good, thanks very much; and I set the pen aside — properly capped, of course.

 

I picked up the pen not even two days later, and to my utter surprise, it wrote (“Sunday, 10 October 2021” below) extremely faintly. I thought the ink may have dried out somewhat in the nib and feed the pen was hard-starting, but there was no skipping or breakage in the lines of ink, so that wasn't what it was doing. Pushing the nib a bit harder, I got slightly more colour out of it, but it still looked nothing like Waterman Mysterious Blue ink.

 

Eventually, I primed the feed by turning the piston knob, and the colour became a bit closer to blue (or teal-black). I've marked out in the image below —with straight magenta lines — where or each time I primed the feed. Only after the nib and feed were literally dripping ink (and cleaning it up with a paper towel) did the colour of the writing return to what I thought Waterman Mysterious Blue ink looks like.

 

 

I emptied the contents of the ink reservoir into a sample vial, then flushed, cleaned and dried the nib unit. After reinstalling the nib, I gave the pen a fresh fill from the same bottle of ink as before, and started a second test sheet to check if the issue persists over the following couple of days. In the meantime, I compared the ink extracted from the pen and the ink still in the bottle by chromatography, just in case something has contaminated or denatured the ink from the first fill after it passed through the nib and feed into the reservoir.

 

 

Nope, it doesn't appear to be the case.

 

What it does look like, however, is that the blue and violet dyes have somehow been filtered out, such that then nib was only laying down the turquoise dye in the ink when I wrote with it after it was capped for a day or so, as opposed to the ink evaporating and getting more concentrated with dye (thus appearing darker).

 

 

Can anyone explain what's actually happening?

[tde44x]

If you are storing capped, nib up, it sounds like ink is draining back from the feed delivering less ink volume until you write with it for a while. Perhaps try it again but the pen stored horizontally or if it does not leak ink, tip slightly down.

[A Smug Dill]

14 minutes ago, tde44x said:

If you are storing capped, nib up,

 

No, the pen was resting on its side the whole time while it was unused.

[halffriedchicken]

I would check to see if the tines on the nib could be widened to improve flow or the odd chance that the feed has been manufactured with a defect or has been damaged. If the thin lines are the normal lines when inked with a cartridge and not dipped then I would guess the nib tines could be widened. Did you check the gap between the tines when the pen is not inked? If it's too close I would floss the nib. I would be surprised if the feed was clogged from your description so I would check to see if the feed has been manufactured properly of if there is damage and see if the channels look clean and clear.

[Mezu]

You should write with the pen for some time (e.g., several pages) after inking it (post cleaning) to see if the color is consistent with your expectations of that ink.

 

If the issue comes later, then my guess would be that the ink is indeed drying within the feed and narrowing the channel.  As you suggested, it's then reasonable to assume dyes associated with large particle sizes would be filtered out until the narrowing is undone (if at all).

[maclink]

I've had crud in the ebonite feed of one of my Leonardos.  Flushing didn't get it out either.  I didn't see it until I inspected the feed channel under magnification.  Once I did so, the ink starvation issues I was having went away.  However, my symptoms were different from yours but who knows? Feed issues may well manifest in different ways.

 

Whenever I've had nib issues, the problem is consistent.  It doesn't improve over time unless I press on the nib while writing to gradually separate the tines a bit.

 

[TSherbs]

Seems like your ink in the pen is having a chemical reaction with something else while it sits. That does not look like a starvation issue to me. It's either changing after exposure to the air, or after contract with some other compound.

 

But heck if I know what.

[TSherbs]

Put the ink in another pen, and see what it does after sitting a day.

[sansenri]

it's the "mystery" with this ink

 

this is what my bottle does

 

at the top, just written, at the bottom written the day before

 

 

at the bottom written the day before (same as in first photo) in the middle written 2 hours earlier (same as in first photo), at the top just written

 

 

[TSherbs]

@sansenri So, it starts blue, but then changes to the aqua color over time after it is on paper?

[A Smug Dill]

Thanks for the suggestions, everyone.

 

7 hours ago, Mezu said:

You should write with the pen for some time (e.g., several pages) after inking it (post cleaning) to see if the color is consistent with your expectations of that ink.

 

It was, when the nib unit first came back from the manufacturer, and I filled the pen with Waterman Mysterious Blue and wrote several A5 pages with it, prior to reporting back to Santini that all was good. (The repair was for something else entirely, and had nothing to do with how the nib wrote.)

 

7 hours ago, halffriedchicken said:

Did you check the gap between the tines when the pen is not inked? If it's too close I would floss the nib.

 

There was nothing wrong with it in that regard when I wrote the first few pages with it. The ebonite feed would be very saturated immediately after filling the pen, even after I blotted off the excess with a paper towel. There was no problem with the ink that was in the feed flowing down through the nib onto the page.

 

5 hours ago, TSherbs said:

Put the ink in another pen, and see what it does after sitting a day.

 

I'm pretty sure I already have another pen recently filled from the same bottle of ink (which I only had for a couple of weeks) somewhere. I just have to remember which one!

 

That said, it isn't really the ink I'm particularly worried about. In any case, the chromatography tells me that the ink inside the pen's reservoir after a couple of days is no different apparently from what's in the bottle; what's happening is confined to the ink inside the feed.

 

2 hours ago, TSherbs said:

@sansenri So, it starts blue, but then changes to the aqua color over time after it is on paper?

 

The line that reads, ”Emptying the entire reservoir through the nib…” on my first page of writing sample shown above is still dark blue today.

 

…

 

What I will do is change the ink in the pen to something else with multiple dye components.I just thought I'd capture and document this strange phenomenon before I proceed; it isn't something I'd actually want to replicate.

[TSherbs]

Yeah, it's a head-scratcher....

[Daosus]

I've had that happen when the ink evaporates and you get a drop of water on the feed.  Since I store my pens nib up (not sideways like this pen), the ink drains from the top of the feed, and when the water drops get on it, it dilutes the ink.

 

 

[sansenri]

17 hours ago, TSherbs said:

@sansenri So, it starts blue, but then changes to the aqua color over time after it is on paper?

Yes, that is what my bottle does. I've been told my bottle is bad (i.e. is from a bad batch).

[A Smug Dill]

[sansenri]

I'm rather convinced it has to do with this ink. As I've mentioned it does this odd thing of becoming lighter with time, with my bottle.

 

Could it have anything to do with different components of the ink separating when you leave the pen unused for some time, and then re-mixing as you gradually use it, in your case?

I can't think of another reason to get darker, but actually change colour tint, otherwise.

 

You could try to see what happens if you "shake it before use"

[A Smug Dill]

2 hours ago, sansenri said:

You could try to see what happens if you "shake it before use"

 

Oh, I've tried that early on, and then again several times. It doesn't affect the ink that is already in the ebonite feed, so there is no observable effect. 

[fabri00]

Try to change ink, to see if the problem is the ink or the pen.

[InesF]

Hi @A Smug Dill.

 

No mystery here. Funny, I had the exact same problem with my Santini Libra with exactly the same Waterman Mysterious Blue (pH 2.9).

 

The reason is strange, but follows some logic: when the tip of the nib is in contact with the washer or the screw in the cap (holding the clip), the metal (I don't know if it is copper or iron) works like a catalyst and lets the ink change colours. The contact can be made by a tiny small droplet of condensed water, for example.

 

The solution is the same simple: remove screw and washer, cover them with clear nail polish, let them dry completely (!!!) and put them back.

Alternatively: send the pen back to Santini, they know this problem already....

[A Smug Dill]

1 minute ago, InesF said:

No mystery here.

 

Thanks for the explanation!

 

2 minutes ago, InesF said:

The contact can be made by a tiny small droplet of condensed water, for example.

 

I did indeed see some tiny beadlets of condensation on the nib face when I uncapped the pen last time.

 

3 minutes ago, InesF said:

Alternatively: send the pen back to Santini, they know this problem already....

 

Santini has already fixed my pen twice and graciously paid for international postage both ways each time, so I won't do that to them. If this is the only ink with which this strange problem occurs, I'm OK with just using some other ink.

 

However, now it makes sense why there would be pitting of the rhodium-plating in the shape of tiny beadlets just off the side of the nib slit, which was why the nib unit was sent back for repair in June. So it wasn't that Diamine Prussian Blue was corroding the metal coating on account of the ink's pH value per se, I guess.