Fountain Pen Design

Function, Development, Construction and Fabrication

3.1 Making Inks

In the previous chapter Fountain Pen Inks, I summarised my findings by showing the degree of variations of our ink. In how far they would affect the behaviour of fountain pens, I didn’t know then, hence I decided to contact and visit our ink supplier, trusted for decades.

Before, when I visited experts, they had been open, listened to my research and discussed the meaning of the results. I found these meetings always fruitful, for both parties.

However, when I arrived at the ink manufacturers, they were quite reserved about informing me of their product, it was almost like saying: “No one has ever asked us these questions. Who are you to challenge us?” It almost felt like blasphemy.  I was told that they had been in the writing ink business for generations, a magician could have not been more secretive. After a cup of bitter coffee with dry, stale cookies, they send me away without showing me their production facility.

Luckily, the guys from the dye manufacturers (BASF) were much more open. Quite jovial, they informed me that writing ink would just be like dirty drinking water. It’s simply tap-water, containing two to five per cent dye, a pinch of each, preservative and detergent. From other ink users, they had learned about problems with black ink, containing about five per cent dye.

Then they were silent, like saying: “That’s all the information you need. You can go now.” I had not even got comfortable in my chair and the coffee was still too hot to drink. They had a laugh about my long face.

But then they duly listened when I told them a few details about my findings and calamities and were quite happy to enlighten me in areas where I had expressed my uncertainty.

Sometimes, I played a bit dumb to gauge how much they knew about fountain pen ink. Once I had realised that their information backed up my findings, I trusted their advice.  I had to because I am not a chemist, after all, not at all.

They were the chemists and got quite excited when I related the more physical characteristics of the ink with the function of fountain pens. Obviously, they liked hearing about the practical application of their work. And of course, we went into the magical field of speculation, researchers’ playground, the place where new ideas grow.


Two weeks later, much better equipped, I approached my hesitant ink manufacturer again.  This time, backed by my findings and concrete data, I confronted them more astutely. Soon I realised that they had no idea what I was on about, capillarity, surface tension and hygroscopy.

Once challenged enough and before losing face too much, they showed me their historic-looking pH‑meter, the least important instrument as my studies had shown.  Then we walked across the yard to a metal shed, the place where they shovelled some kind of salt into a 50-gallon metal drum (rusty, at places), mixed it with a propeller on a long rod driven by an electric drill … their ink manufacturing plant. Giving me a haughty look, they didn’t tell me what that salt was.  Either way, I was not impressed in the least.

With the help of my friends from the dye manufacturing company (they gave me 1kg bags of all the ingredients), I began “cooking” my own ink. Including all ink tests, the total variation was around 4%, I was thrilled. As expected, the results of my pen tests not only showed less variation but most importantly, they appeared more meaningful, they occurred as anticipated.

Just out of interest, I investigated tap water with my ink test methods and found that the changes of tap water accounted for about a third of the variations I had measured with the ink.

A bit more info on this. Initially, I compared water samples taken from my laboratory tap in the mornings and evenings; they were the most stable. The most extensive variation were samples taken on Friday afternoon and Monday morning after the water had been resting in the pipes for two days. After this weekend, I used distilled water, to reduce the water’s impact and that was how I achieved the 4%. From then on I only used my ink for all the testing.

I kept on experimenting with the water for my ink. Furthermore, I found out that the morning-evening variations during summer were larger than during winter. Later I also realised that boiling the water before mixing the ink had enough calming effect to produce a consistent enough quality. Nevertheless, distilled water was used elsewhere in the company thus, for now, in the laboratory, the cost was of no consideration.

My aim was to develop the functional parts for a fountain pen. For this, I needed an ink with a narrow range of variation.  I found out how to make ink but this was only another of the many byproducts which came out of my laboratory, along the way.

Yes, along the same way, I yet learned more about ink which I will tell you about now.

Components of Ink

As you heard in my adventures with the dye chemists in 1978, they considered fountain pen inks mainly being “like dirty water”. Inks are predominantly water with traces of different additives, which give them colour, physical and paper adhesive characteristics. Since the most crucial ingredient is the dye, I would like to spend a bit more time on it and tell you the result of my studies.

Photo 1 — Edge of a piece of paper (internet)

Photo 2 — something written on paper (internet)

Dyes have been around for some time, and there are many types, but here I only want to elaborate on dyes for fountain pen inks.  Ink dyes are coloured substances, which have the ability to compound with, meaning to adhere to paper, see photos 1 and 2.

This is not the result of a chemical reaction, but the dye and the paper fibre are held together by the attraction of adhesion. Adhesion describes the bonding between molecules of different materials.

Ink dyes dissolve in water. The water is the transport agent, which moves the dye inside the fountain pen which disperses the ink to the paper where it evaporates. At that time, the bond with the paper fibre is established.  In contrast, pigments are insoluble, they remain in suspension and have no affinity to the substrate (paper).

Why do things have colour?  Like dyes and pigments, all things appear to possess a particular colour because they absorb most colours of the white light shining on them and they appear to the eye in the colour the surface reflects.  This colour must be contained in the light shining.  You can test this when you filter white light with a blue filter and only blue light shines on a red object, it will appear black because there is no red light contained in blue light.

Acetic Acid

The ink dyes we used thirty years ago belonged to the group of basic (high pH) dyes.  Their pH value is compensated by adding acetic acid (link to Wikipedia) (as present in vinegar) at a very low concentration. Inks are generally slightly acidic, which causes the mildly pungent smell of the ink.  It assists the uptake of the dye onto the paper fibres and improves the stability of the ink and its colour.

If you want your ink to stain your paper more (have a more vibrant colour), add a few drops of that stuff. You will need to experiment because the type of paper has a considerable impact, in some cases, it can blot through.

Acetic acid is one of the oldest chemicals and was used already in alchemy. Before wine had not been treated chemically to the degree as it is today, it occurred naturally, especially in stored dry wines and was found as clear crystals deposited either on the cork or at the bottom of the wine bottle.  Besides other acids, the crystals are also formed from tartaric acid (link to Wikipedia).  In German, the latter is known as Weinstein meaning wine-stone.  It has about the concentration of domestic vinegar acetic acid has a pH of 2.4, thus quite acidic.

It is hygroscopic, which means it absorbs water from the environment, which unfortunately causes, at high humidity, ink to smudge again. Acid is also the reason why ink forms crystals when it dries out in a bottle, for example. It is quite safe to dissolve them by adding small amounts of water to the ink; the same applies when the ink begins to smell pungent.

Recently, I was informed by a reader (who is a chemist) that non-ionic dyes (pH neutral) have become available, which are soluble in water.  This eliminates the need for adding acetic acid. However, I assume that another kind of acid will have taken over the task of ensuring the ink absorption into the paper.

Poly Ethylene Glycol …

… also known as PEG or glycerine, I added to affect the drying characteristic of ink under certain conditions. It reduces the drying speed on the nib and feed but shortens the drying time on paper.  Somewhere I have written about that, but where? If you find it, let me know, please.

And as I elaborate in the chapter about the feed, the flow of the ink is mainly determined by the shape of the feed, the surface-active properties of its material including those of the ink but less its viscosity which is only mildly increased through adding a tiny bit of glycol.  More about that, later.

Detergents …

… reduce the surface tension of fluids, and some people believe it is instilled into ink to increase its flow, and no doubt it would do that. I invite you to a test but use a fountain pen that you can do without. Just add the smallest amount of detergent (one grain of washing powder to a cartridge) into your ink.  It will end in a disaster, and your fountain pen may never work again.

The maintenance of the predetermined, certain degree of wettability of fountain pen components carrying ink is critical, however, it is created to a narrow specific range by other means, which I described in the chapter on  Feeds made of Plastic.

Phenols …

… or other mild fungicides prevent mould from growing in ink. Therefore, don’t drink ink; you could experience minor effects of poisoning (after about ten litres) and staining of your teeth.


The story on this page shows you how unpredictable the challenges are that face an ingeneer trying to get a fountain pen to write, and suddenly he needs to make his own ink.  Never a dull moment, is there?  In the next chapter, I will tell you about the Perfect Ink.


Amadeus W.

29 July 2014

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