For decades, I've been using Rapidograph pens for my artwork. And, though I've tried a few brands of ink that I thought might be fine, I keep going back to Koh-I-Nor's product-specific ink. Here's why: The pen nib is extremely narrow (especially with a Size 0 point or finer) and anything other than the thinnest ink can clog the pen, perhaps ruining it.At the other end of the spectrum, some thin inks may not have the darkness - look opaque enough, in use - for the results you want.This ink earns five stars and more, and - even if you're a prolific artist - each bottle will last a very long time. Get Koh-I-Noor. It's worth it.

Parfait

Be very careful--the photo listed as of 8/24/20 does not match the description. The photo is Rapidraw but the description is for Ultradraw. I have also received Universal when ordering Ultradraw. They are three very different products.This review is for Ultradraw, which is a pigment-based ink specifically designed for technical pens. It is waterproof, lightfast and archival quality. The Universal ink, which comes in an almost identical container, is dye-based and not lightfast.I use Ultradraw in most of my technical pens including Koh-I-Noor Rapidographs, K&E Leroy, Alvin Reform, and Faber-Castell. It works very well in each of these brands when used on good quality paper. I do most of my work with the smaller nib sizes--.13mm up to .35mm--and this ink flows very consistently..I have also had good success using Ultradraw in Rotring Isograph pens as well as Staedtler Mars 700 and Marsmatic pens. The only reason I don't currently use Ultradraw in these pens is because I have a good supply of both Rotring and Staedtler ink. When this supply is exhausted II'll switch these pens over to Ultradraw as well.I don't necessarily prefer the Ultradraw to Rotring Isograph Ink or Staedtler Marsmatic 745R ink, but I have found it to be just as good and less expensive--especially when purchasing the much larger 250 ml/8 oz bottles.I frequently put down watercolor washes over the top of drawings and have never had this ink run or bleed as long as it's given time to dry. I'm not sure what the manufacturer recommends but I frequently put down a wash within 30 minutes of having finished a drawing. However if it's a drawing I've invested a lot of time in I'll let the ink dry overnight.Clogging has not been a problem as long as I use good paper and properly maintain my pens. Although waterproof when dry, this ink cleans up easily with water. I typically partially disassemble and rinse the nib each time I refill the cartridge unless I will be using the pen heavily for several days in which case I'll clean the nib less frequently.Be very careful not to overfill the ink cartridge. If it's too full--depending on the brand of pen--when you reattach the cartridge to the base of the nib assembly it will force ink up through the base into the breather gap cut into the nib threads. You'll know if you've done this because ink will be forced out of the threads at the tip of the pen and you'll likely have it all over your fingers and possibly all over anything else you've touched.Blocking the breather gap prevents ink from flowing properly--regardless of the brand of ink.To fix the problem remove the ink cartridge, partially disassemble the nib assembly (but not the nib itself) and rinse and dry the nib threads as well as the matching threads in the base. Reassemble and make sure you only fill the cartridge to within 3/8" of the top.When not in use I store my pens nib-up. I've found that even so the pens almost always start immediately when I use them next. If they do hesitate I use a Koh-I-Noor bulb syringe to draw a tiny bit of ink out of the nib, which I've found works much better than tapping or shaking.Koh-I-Noor Ultradraw is my go-to ink for pen & ink drawings and for use under watercolors. While I can't say it's better than Rotring or Staedtler technical pen ink I've found it to be just as good and usually less expensive.I also highly recommend this Koh-I-Noor Ultradraw over Koh-I-Noor Universal ink. The Ultradraw is archival and very opaque, while the Universal is dye-based, less opaque, and not lightfast.

Been using Koh-I-Noor ink for a long time. Hard to get where I live now. As good as it ever has been.

Tinta con opacidad suficiente para cubrir y no dar dobles pasadas. Se desplaza suavemente por la superficie del papel perfecta para los estilografos RapidoCraft de la misma marca.

Ils sont vraiment beaux! Bien hâte de les essayer pour un nouveau projet....Un artiste heureux 😁Recevez mes salutations

I have used this ink for years and I swear by it. I illustrate all of my published true crime and nonfiction books, and now children's books, with Ultra Draw. With this ink you could put your drawing underwater and it would not fade or wash away. I have even drawn on glass with it. My real reason for commenting is that I have stumbled on a super way to clean my pen points and technical pens of Ultra Draw. The only problem with an ink that is impervious to water is how to clean your tools. I add a spray cleaner called Scrubbing Bubbles to a glass of water. You drop in your pen and the water goes instantly black. Hope this tip helps. It sure works for me. Robert Graysmith

This is the best ink for drawing with a nib pen, or mixing with liquid watercolors. It dries completely matte, waterproof, and reasonably dark. I've only found darker black with certain dry-pigment watercolor pans and tubes, which are of course water-soluble. This ink also can be used in technical pens, and it dries very quickly on paper. I've also never had this ink develop any rotting odor, unlike some Higgins inks. However, I use this variety so often that a bottle's never sitting for months. I received the correct item from Etailz ! Previously, I had ordered from Best Source Office Supplies & received the black Koh-I-Noor 'Universal' ink, which doesn't dry matte. (The colored varieties of that universal ink are pretty great, however.)

Nearly impossible to find this product in stores but the best ink for rapidograph

I ordered 4 bottles the Ultradraw ink pictured, but received the Universal (al 4 bottles). This was simply a fulfillment issue from BestSource OfficeSupplies, and I will likely not order anything being sold from them again.However, I will still review the Ultradraw ink (ended up ordering more from another supplier). The ink is great, but honestly I don't use it in my Rapidiographs. What I use this ink for is nib and brush inking. It's rather thin (obviously), but flows great with the Hunt 102, saturates brushes amazingly well, and has a long enough open time to be great at these applications. Not to mention it is DARK when put down by a brush. This ink does work great in Rapidiographs, but I don't require the long open time from the Ultradraw ink (I tend to use the Universal for that, which is why I didn't complain about the order error). However, for first time technical pen users, this ink may save you the hassle of a little more frequent cleaning.The only con about this ink is the scent. This ink is thinned to work well in technical pens, and this often involves the use of a solvent. This ink has a VERY strong solvent smell which may annoy some people (I know it annoyed me when I first started using it. Now I actually enjoy it).Over all, a superior Indian Ink that works great in technical pens, nibs, and brushes. Just don't order it through BestSource OfficeSupplies.

very high quality ink .