An alternative look at ink wetness

[InesF]

17 hours ago, Frank C said:

Thank you for sharing all this work. I do find the range of pH values interesting. I guess that fountain pens are able to tolerate these strongly acidic or basic inks. 

Hi Frank C.

Yes, almost all modern fountain pens can deal with neutral, weak and strong acidic inks - no problem to expect. I used Waterman Green/Blue (pH ca. 3) in a Waterman Maestro pen for ca. 20 years and cleaned that pen about once every two or three years - however, it was always in use and never dried out.

[InesF]

11 hours ago, samasry said:

Very good  study.   It is becoming more and more  clear  to me that paper is the weakest link in the entire  fountain pen writing chain.  It is the  hardest to study and the paper manufacturing vector is hardest to sway.

Hi samasry.

Indeed, paper is a strong player in this pen-ink-paper triumvirate. If you found a paper that works well with your pen and your ink, stay with it!

[LizEF]

6 hours ago, InesF said:

Mountain of ink lists currently 1524 ink reviews - I guess, there is some room for surprises! If I think on all permutations of two ink mixtures or, god beware, when I think of mixtures of three inks, it makes me slightly dizzy.🤫

Dizzy indeed!  One could have an entire company dedicated just to testing and documenting mixtures and they'd never run out of work!

 

6 hours ago, InesF said:

What about a combined lecture series about all these aspects of fountain pens, inks and papers as a part of a pen show? I mean, with announcement and a special dedication for beginners. What's your opinion, can this be something interesting for a show organiser?

I would think it would be extremely interesting!  While there are many in our hobby who don't care about more than inking their pen and writing, the number of those interested in experimenting seems to be increasing - enough that I'm sure interest would be high.

[Frank C]

7 hours ago, InesF said:

What about a combined lecture series about all these aspects of fountain pens, inks and papers as a part of a pen show? I mean, with announcement and a special dedication for beginners. What's your opinion, can this be something interesting for a show organiser?

I do know that I would be interested. I'm not sure where you're located, but the San Francisco Pen Show is coming up. Living in the Bay Area, they are free-thinking and open-minded. They might be able to include this.

 

https://www.sfpenshow.com 

 

[InesF]

Thanks Liz and Frank C for the motivating me!

 

August is a bit too close. I thought more about end of 2021 or early 2022, or even later.

 

And no, it was not meant as a single person lecture. Here are many highly experienced people of all aspects of pen and ink - my guess was to have a FPN-session! Of course, such a session will need some organisation and - most importantly - members who want to talk about their experiences. If, let's say, five or six FPN members would each give a short talk, such a session may offer enough experience to specifically attract people.

Europe would be nice for me, but US is possible in 2022.

[LizEF]

2 hours ago, InesF said:

my guess was to have a FPN-session! Of course, such a session will need some organisation and - most importantly - members who want to talk about their experiences. If, let's say, five or six FPN members would each give a short talk, such a session may offer enough experience to specifically attract people.

That does sound interesting.  And you'd think it would generate more interest in the show from FPNers - go see a few of our own.   I think you should pursue it.

[InesF]

Challenge accepted, @LizEF 🤩

[LizEF]

35 minutes ago, InesF said:

Challenge accepted, @LizEF 🤩

[Frank C]

I used to try to attend the San Francisco and LA Pen Shows in the pre-pandemic era. I would consider traveling further to hear @InesF talk about ink chemistry and physics. I would also like to hear @LizEF talk about ink and extra fine nibs; she would have to promise to leave her sphinxes and wizards at home—trouble seems to seek them out. At the moment, it appears they are hopelessly trapped, but I have a feeling they'll escape to pursue some further adventures. 

[LizEF]

27 minutes ago, Frank C said:

I would also like to hear @LizEF talk about ink and extra fine nibs

That's only because you haven't heard me speak.  There's a reason my videos are "ASMR".

 

28 minutes ago, Frank C said:

she would have to promise to leave her sphinxes and wizards at home—trouble seems to seek them out.

Given that they live inside my head, and me traveling without my head seems both unlikely and unpleasant, I'm afraid I can't make such a promise.  Further, there are many more people where they come from (well, sort of, the others live in other universes - I have ~4 universes in there), so if I come, lots of people come with me.   And they all tend to live in the middle of trouble...

 

33 minutes ago, Frank C said:

At the moment, it appears they are hopelessly trapped, but I have a feeling they'll escape to pursue some further adventures. 

The universe is currently accepting suggestions regarding said further adventures.

 

[InesF]

7 hours ago, Frank C said:

I would consider traveling further to hear @InesF talk about ink chemistry and physics. I would also like to hear @LizEF talk about ink and extra fine nibs; she would have to promise to leave her sphinxes and wizards at home—trouble seems to seek them out.

Thank you Frank C!

Sounds like a good deal - if I talk about ink chemistry, Liz will balance my boring talk with speaking and writing in Riddlese, the writing, of course, with an EF nib.

As the curious person I am, I would like to welcome all these Wizards and Sphinxes, Heroes and Rogues ...

[InesF]

This time a smaller update - it's vacation time and I do not have access to the balance. Furthermore, hot summer air makes precise measurements a bit tricky, as I can only do it during the early morning hours.

 

Please find below the updated ink properties table which is sorted for ascending surface tension. The same as before, the inks are classified into three categories: low surface tension in pink, medium surface tension in pale blue and high surface tension in green background color. The pH values are colored pale and darker red for acidic, blue for alkaline and colorless around neutral (6.8 to 7.2).

 

The next update will be in August 2021. Stay tuned for more data and for a new theory about fountain pen nib wetness (which needs only some more measurement data to be formulated).

 

Have a nice summer!

 

[txomsy]

Thanks for the update. Enjoy your vacation.

[Frank C]

Wow, that's a lot of work. I'm always surprised by the very acidic inks. Please keep up the good work. 

[RJS]

Fascinating work! Thank you.

[InesF]

Vacation was nice, but it's over now - time for a data update.

 

A total of 49 inks are measured now for surface tension, viscosity and pH-value. 16 of them were written with two different pens at two (sometimes 3) different papers types with measuring ink consumption per line length, line width and ink per paper surface area was calculated.

Some of the inks may be exotic for your region, however, only Ferris Wheel Press and Colorverse are the exotics in my region (besides some of the limited edition inks). All the other are quite commonly available for me, most of them are always on stock in the local shops.

 

This is the condensed analysis data table, colored and sorted as before.

Oh, I see, I didn't match the pH colors exactly. The two J.Herbin shimmering inks were measured without particles - I took the supernatant ink after letting it settle for a while.

Please remember, inks with addition of Gum Arabic (G.A.) were trimmed for calligraphy use. However, they behave still quite nice in my fountain pens!

 

Instead of the extended data table, here the graphical presentation of the writing data.

 

Correlation coefficients are not so high. Considering all measurement uncertainties, however, they are not that bad either.

 

And then I tried to combine the data for both pens (you remember, I did not before, because they have slightly different tip sizes) for the ink consumption per line length and per area:

 

OK, that was a bit a surprise. The correlation coefficient improved with the increased number of data points and, all of a sudden, outliers became visible (in the ellipses). But one after the other:

Still valid: surface tension is the most important ink property determining its wetness - the lower it is, the wetter an ink.

Still valid: the paper type plays an important role - absorbent (low quality) paper increases line width, feathering, spreading and bleeding and increases the amount of ink which is laid down compared to 'fountain pen friendly' paper.

Still valid: ink viscosity has no effect on ink wetness (as long as the ink is able to flow through the capillaries - and even the most viscous ink did flow quite nicely through both my pens).

New insight: the amount of ink laid down per area (line length times line width) followed similar rules for both the tested paper types (parallel correlation lines). As the inks spread out on absorbent paper not only in two but in three dimensions (sucked into the paper), the total ink delivery was still higher than it was on non-absorbent paper.

Outlier identified: in the current data set the clear outliers are the data points from the only alkaline ink (Iroshizuko) - clearly outside measurement deviation. Other may be there but currently hidden in the data point cloud.

New hypothesis: alkaline inks may interfere with the paper a bit differently than what can be predicted from its surface tension. The Iroshizuko ink has a low surface tension (which would suggest increased ink delivery) but the delivery amount was more in the range of mid to high surface tension inks, although it feathered and spread on absorbent paper! The consequence: I had to test more of the neutral and alkaline inks for the upcoming principal component analysis.

 

So far the news for this week, next update in ca. two weeks.

 

I'm open to discuss the data and still hoping you can see something that I missed! Thank you for reading!

[Frank C]

I enjoy reading your data and conclusions. You've put a lot of work into this. Thank you, and please keep up the good work. 

[RJS]

Hmm, the ink wetness definition you find throws up some questions. For example, I tested Waterman Serenity Blue (very high surface tension) and R&K Scabiosa (very low surface tension) in the same pen on the same paper. Serenity Blue laid down a lot of ink and felt extremely well lubricated, while Scabiosa laid down substantially less ink and felt as dry and chalky as an ink can feel. In this one instance it would appear that surface tension doesn't play a prominent role in wetness. Maybe the Scabiosa disliked the combination of a fairly broad and very smooth nib on coated paper?

 

Edit: The high surface tension of the Serenity Blue did show itself in terms of the ink pooling and drying slowly, and then showing considerable sheen.

[LizEF]

43 minutes ago, RJS said:

Serenity Blue laid down a lot of ink and felt extremely well lubricated, while Scabiosa laid down substantially less ink and felt as dry and chalky as an ink can feel.

Please keep in mind that flow (wetness) is not the same as lubrication, and while wetter inks are often better lubricated (and drier inks often more poorly lubricated), that is not always the case.  I suspect:

1. Increased flow can improve lubrication, even without a lubricant
2. Decreased flow can reduce lubrication, even with a lubricant
3. (Some?) lubricants may lower surface tension, thus making an ink wetter

...but...

1. I don't know that all lubricants (I assume there are multiple possible lubricants for inks) lower surface tension.  (Technically, I don't know that any do this, I just suspect it.)
2. Even if a lubricant does lower surface tension, it's possible that the surface tension was high enough before addition that the ink still seems "dry" after the lubricant is added (thus, a dry, well-lubricated ink).
3. It's possible that surface tension is already low enough that the ink flows well without a lubricant - thus giving us a wet but "scratchy" ink (which may be mistaken for a "dry" ink).

It took me a long time of using many inks in the same nib on the same paper before I was able to determine that flow and lubrication are independent from each other.  And even now, it's difficult for me to always trust what I'm sensing, since it's subtle and utterly subjective.  (Some days I really, really wish I had a lab, training, and equipment to measure everything scientifically so I could compare facts to my writing experience, but none of that is going to happen, so I'll just have to stick with wizards, sphinxes, and a subjective EF  experience.  I also wish I could start over with what I know now, but there's no way I'm re-doing all those inks, and even if I did, by the time I was done, I'd have enough knowledge to want to start over yet again, ink reviews without end...)

[LizEF]

Thank you, @InesF!  I really enjoyed this last update.  I now need to go review and see if you explained how to measure surface tension.  If it's easy enough, I think it would be fabulous for us to start gathering some sort of community-populated database of ink surface tensions.  (I suspect it's not so easy to do accurately, but still, I'm gonna go back and look.)

 

(And I'm now feeling kinda bad for An Ink Guy as I'm not so sure his massive work measuring ink viscosity gives us anything of use...  )