I get a little buying brand name products on Amazon, but these are the real deal. I've ordered them a few times for my Montblanc fountain pen and they work fantastic each time. And certainly cheaper than buying them direct from the manufacturer.I am relatively new to fountain pens and inks (this is my first ink actually). The color is an intense blue that almost looks black, but in the right light, it looks incredible. I would definitely recommend getting this ink if you love blue.Montblanc Royal Blue is a staple in my supply of inks and has been for years. This is despite a few shortcomings. Even for a royal blue it's a little too purple for my taste. It has no water resistance whatever. Saturation is quite low. So why do I keep buying it at its premium price? My pens love it. The flow and lubricity are above average. Montblanc Royal Blue is a pleasure to write with. It's absolutely safe for lever fillers and aerometric fillers. It's the only ink I've kept in my two vintage Esterbrooks for the six years I've had them.I originally purchased this bottle of Mont Blanc ink in the shoe bottle just for the bottle. It's a great design that makes filling fountain pens quite easy. Bit of a clever design, this 'shoe bottle' holds ink in two open but connected compartments; the section under the bottle cap for filling a pen, and a reservoir behind for refilling the 1st compartment (simply by tilting the bottle). I used to use the same bottle style back in the early 1970s, and glad to see it is still made.The surprise for me was the ink itself -- Mont Blanc "Mystery Black." It's a nice color, not jet-black, but more of a warm, very dark grey. It does not bleed through paper (what I'm using for paper and pen) like many, so I can write on the reverse side of a sheet without seeing any bleed through).Talk about getting what you pay for!In need of blue fountain pen ink I deliberated for a bit, and considered this and two other permanent blue inks. Montblanc Permanent Blue does cost about twice what the other inks I was considering do, but I have had my eye on it for some time, and really the unique bottle shape sold me on getting it (I will never throw away that bottle, no matter what I have in it down the road).Suffice it to say that I am glad I did get this ink, it is excellent. It writes very smoothly, dries reasonably quickly, is subtly shading on the right papers, and shades very slightly on even cheap paper. The hue is just a touch warmer than what I would consider a "pure blue," but it is very close. It doesn't bleed or feather much at all. I compared it to a Platinum Pigment Ink, sepia tone, and to a Noodler's Bulletproof Black. Both of these other two inks appeared to feather and bleed through the page more so than the Montblanc Permanent Blue; albeit none to any considerable degree, and to be fair the Montblanc is also the lightest in value of the three, but in the end it did out perform the others.I almost exclusively use permanent inks and therefore was curious to see just how permanent this one was. Writing and sketching a little, and then leaving it to dry about half an hour I then saturated the page and let it sit in stagnant water. The ink remained entirely legible and there was no appreciable degree of additional bleeding. There was only a slight amount of run when agitated while wet, less so than I have seen in the Noodler's waterproof inks... So this is definitely permanent under wet conditions (I have not tried solvents on this ink).The one place that it does under-perform compared to the Noodler's and Platinum inks is that it can be easily and significantly faded using an eraser, the others are much more permanent in this.This ranks among the best inks that I have used and is worth the price if you want a premium quality ink to write with... and a gorgeous bottle.I got the Permanent Black. I hate black inks because they are boring to me and are never pure-black. Usually a dark gray that looks like watered-down black. I needed an ink for general work related stuff and decided to give this one a try. As soon as I uncapped the bottle, I knew that this was something different. The consistency is more viscous than your normal non-permanent inks, almost gel-like. The black is blacker than black. There is absolutely no translucency to it at all. I inked up first my Pelikan M800 and started to write with it. I was amazed at the amazing flow of the ink, the absolutely crisp line, and the matte finish once dry. The M800 I have is quite dry, and this ink made it glide effortlessly on the paper. It has an obsidian quality to it, reminds me of laser printer toner. It is completely waterproof. As in, the lines do not even fade in water, windex, bleach, or alcohol. The "top layer" of the line, basically the solid particles, will wash off, but underneath you will have a perfectly black line. Pretty amazing actually. This ink should not be used in "occasional writer" fountain pens that sit in a drawer inked up. This should be used in that daily writer every-occasion pen due to the high solids content. It could potentially leave residue in your pen if left sitting for weeks or months. But I knew this going in. Also, the thicker consistency might make it a good candidate for pointed-pen calligraphy, and will try it once my nibs arrive. In the meantime, it now lives in my MB 146 EF fountain pen, and lays down crisp, consistent, and ultra-black lines. You can't go wrong, and as another reviewer mentioned, I believe this is the new standard by which all black inks should be measured by.This review is for the "permanent black" ink from Montblanc. It's a bit more expensive than the regular inks, but by shopping around and watching price fluctuations you can buy it for 21 quid. You don't need to pay more than that!As you can see in the attached photo, I used "mystery black" which was given almost a fortnight to dry, and then "permanent black" which was given just two days to dry. When water was splashed liberally onto the paper the writing in mystery black was obliterated, but the permanent black shrugged it off for the most part. You can tell the ink has been assaulted with water, but it's still legible.From now on I'll be using this ink for any writing which could be exposed to the elements! Envelopes, labels, field journals, et cetera.I bought these cartridges to try out before buying a bottle of what’s supposed to be one of the nicest green fountain pen inks. Put a cartridge in my Faber-Castell Neo and experienced hard starts and skipping until the pen was not writing at all. Spent a lot of time today trying to fix the flow of the nib until I realised squeezing the cartridge helped...until it didn’t. Swapped the cartridge to a Jinhao which I know has a wet nib and is causing skipping even in that pen. Tried a different cartridge too in case the first one was a dud, some improvement but still skipping and drying out.I have used this colour for nearly 20 years but no more. The reformulated ink didn't have a warning that it was no longer permanent as the IG was not present.The inks performance isn't as good as the old formula it bleeds into paper more easily and runs with slightest amount of moisture.If they bring back "classic" midnight blue I'll come back to it until then I am seeking a replacement. I am a very disappointed Montblanc customer.Looking for a dipping ink pot for my art work. Montblanc shaped bottle looked solidly made and the prefect height. Added feature of being able to tip the bottle into a smaller well near the cap was a great design plus.Screw top cap is robust and easy to open or close.This mystery black ink is not a permanent ink. It was interesting from my art point of view to deliberately to spill water over the dried ink for effect. After completely washing away the black ink there was residue sepia coloured ink marks which was easy to read the original text I wrote in mystery black. Will be buying more.No ink flow, poor quality print on packaging, definitely not Mont Blanc Ink. Spent ages trying to figure out why my pen was "broken". Inserted a proper Mont Blanc black cartridge and everything is fine again.Amazon needs to get a grip on t his - fed up of fake crap being presented as the real thing.0/10 for the supplier 0/10 for Amazon