Koh-I-Noor Hardtmuth is a famous manufacturer of (not only) writing, scribing and painting "tools" and accountrements of all kinds, with over 200 years of continuous history from former Austro-Hungarian Monarchy to current Czech Republic. Their sortiment is broad enoght to cover whole range from hardcore development engineers through different artists by trade to hobby pencil cartoonists. This company is the original, first succesfull creator of todays most simple and notorious writing instrument-a graphite pencil in a wooden stick.
From the brief above is quite clear, that Koh-I-Noor is realy not specialized in inks. They have a basic, but usefull range of comon grade writing and india inks in several colours, but kind of "just by the way", they have in portfolio
Koh-I-Noor Document Ink Black
I can´t say what is it based, as this is kept secret as far as I know. It is not an iron-gal ink, it is not a graphite ink, no way it is a more stable breed of "coloured writing lotion". Probably it is one of the few formulas which work with chemical interaction with celulose in the paper.
The colour is dark grey-black or black-grey with distinctive greenish hue, depending on paper and pen combo. It darkens over period of several minutes to several months into flat black with greenish hue.The more it darkens, the more it is resistant to any kind of wash-out.
It is awarded ISO 14145-2 and BS 3484-2. The latter is a British norm for permanent record inks, and as the Brits are quite hardcore (another word would fit here better...) about what to consider "permanent record", it means quite a lot. I´m not sure how much pH neutral it is, but will update if I get the info.
The ink is a bit more viscous than most others, but flows very well and have some lubricity. Basic Parker Quink feels like running water with no lubrication in compaison, from my point of view on distant memories-but keep in mind this is nib-affected feeling. The viscosity causes very little feathering, even on most low quality papers, but also makes fine nibs to produce M line on some quality papers due to surface tension effects. But the width of the line is consistant, no blots. Frankly, no blots at all, except some realy poor papers or papers of very fibrous nature with "open" surface (like kitchen towels...).
Flows well, on some papers almost too fast for my taste, but still not like eg. Quink. Due to its nature, after about 15-30 seconds, depending on the nib, it tends to develop a bit of "skin" and makes the pen a false starter. If the nib has a "baby bottom" grind, it can be realy troublefull to start it again. From wet nibs on quality paper, it produces a realy deeply saturated line, embedded to rock bottom into the paper. From dry writers, it can be kind of greyish, but this realy does not alter the endurance of the line. There may be some trouble with drying up the nib in some F writers with smalish and/or fine compartmented feeds during prolonged period of fast writing.
On most papers, is dry almost instantly (2-3 seconds).
I posted some general info about torture tests I subjected this ink to, from 2008 to 2014. The post is in the Inky thoughts section, here:
I must add, that the statement "does not clog the feeds" is OK, but after some testing, I´m sure I wil have to give a good bath to my pens, as the M nib Hero 100 writes dryer now than it should. Well, I used it very sparsely in the last 3 years, albeit it was freshly inked all the time.
The abuse this ink can stand is simply unbelievable. The paper vanishes, the ink remains. No matter how do you make the paper to vanish. This says it all. Some people (with degrees in chemistry) claims that this ink is probably the most durable against sun fading ever created, if good, uncoated paper with low filler content is used.
Here I will quote myself from the above linked post:
Several weeks ago, a clipboard with a day worth of important notes (on poor copy paper, 80g/m2), already a bit soaked in the rain, faceplanted into soaked, liquid clay in a ditch. All was covered to no avail under ochroid mess. So I took it home in a plastic bag, washed the paper gently and recovered every bit of info I had written. This says a lot, when I add the paper was more yellowish-brown-ochroid than white as formerly was... The text was not affected at all.
The pens used in the standard review sampler are both Hero 100 of 1950´s vintage, daily writers of my grandfather for some 2 decades, now exclusive daily writers of mine for 8 years. My granddad used them so much that a definitive facette has developed on both nibs, which gives a kind of italic accent to the line, as my writing angle is a bit different to grandpa´s-but close enought to apreciate how smooth gliding writers they are, especialy on vintage paper.
The water test-I tried to lay down as rich line as I could, to promote the greenish hue which sometimes apears from this ink on some papers, without any shade of compromising readablitiy of the text. So I wrote about one letter in two seconds the top three lines, the bottom in just slow pace-as writing slow, I write even worse pattern than usualy. The test was performed for about 1 minute under hot running water (like 70°C), then soaking like 5 minutes in a bowl of that hot water and rubbing the bottom line with finger. The paper lost the top layers, is one fluffy spot there, but the text is still there. And by the way-there is no alteration to the text after two years maceration in much more agressive solutions than hot tap water...
Generaly, I should apologize for the lack of penmanship screaming out of the paper, I used my pens not as frequently as I was used to in the last 3 years (gap in journaling etc.), no practice either... Also, the sampler was printed with a poor toner cartridge, so the thin grey lines are more nonexistant than anything else, so both samples are freehanded, more in a bit of hurry.
The ink is availible in Czech Republic 50 ml plastic bottle for less than 1 EUR to 1,75 EUR equal, depending on greediness of the stationery clerk, or in a nice, simple glass bottle of 30g for 3,5 EUR. On other markets, the price is usualy similarly low, as far as I know. It is one of the cheapest inks I´ve ever seen, but of the most durable and bulletproof you can ever have.
There is also a blue version on the market, which is not as much durable and was created, as far as I know-because of demand for "nice blue document ink, not that greyish feculence you sell". But there are traces of fading even after just 1/2 year on direct sunlight, which is nonexistant with the reviewed original black formula.
Edited by Frank Savage, 04 November 2016 - 17:43.