is mixing fountain pen inks dangerous

How Dangerous Is Mixing Fountain Pen Inks?

John BosleyFountain Pen Ink 29 Comments

I’ve always heard that it’s dangerous to mix fountain pen inks. Some people have had the experience of mixing inks, only to have solids, or a precipitate form, which can potentially clog a fountain pen. I am usually very careful about completely cleaning out my pen before using a new ink. The main reason for this is that I don’t want the old ink color interfering with the new ink color. To be honest, I was never worried about mixing inks.

Years ago I mixed lots of vintage with no problems. I was on a quest to recreate Skrip Persian Rose and figured that the closest I’d be able to get would be by mixing different colors of Skrip from the same time period. I had two, three and even four-color mixtures going without any issues. While this was my only experience with mixing inks, it went well so I figured there was nothing to worry about with other inks.

Still, so many people talked about the negative side effects of mixing ink, I decided to do a little experiment of my own. Could I get some inks to form a precipitate? Would things mix together without issue? I had to know, so I grabbed my bag of sample vials and started mixing various inks together, two at a time. This started out completely randomly and I didn’t see any kind of precipitate. Two saturated inks? Nothing. Two unsaturated inks? Nothing. Hmmm, how about some iron gall inks? Bam! I got precipitate.

mixing fountain pen inks kwz iron gall

This mix of KWZ Iron Gall Bule 6 and Monteverde Sapphire had no precipitates.

mixing fountain pen inks

This mix has some fairly significant solids. I would not want this in my fountain pen!

The two inks that I mixed that gave me precipitate were KWZ Iron Gall Blue 6 and Sailor Grenade. Maybe one of those was the culprit, so I tried mixing Sailor Grenade with some Blackstone Lemur Lime. Nothing. OK, how about KWZ Iron Gall Blue 6 with Monteverde Sapphire? Nothing. Sailor Grenade with the Monteverde Sapphire? I think I see something!

mixing fountain pen inks monteverde sapphire

Monteverde Sapphire and Sailor Grenade

Since my first and most obvious precipitate was with a KWZ Iron Gall ink and a Sailor ink, how about a different Sailor and KWZ Iron Gall ink? I mixed Sailor Epinard with KWZ Iron Gall Aztec Gold. Once again, I got precipitate. Wondering what would happen if I mixed two Sailor inks, I mixed Epinard and Grenade. I got precipitate. How about two KWZ Iron Gall inks? I mixed Blue 6 and Aztec Gold and got precipitate. I tried a pigmented ink and mixed Sailor Black Pigment with Sailor Grenade and got precipitate.

I wondered what was causing this, so I did a bit of research on ink pH. Other than saturation and manufacturer, this was the only measurable data point I could think of to take into consideration. It turns out Sailor inks are on the basic side of neutral, with an average pH of around 9. Not wanting to pick on Sailor, I found some other inks that I had that were also basic and it turns out that most Pilot Iroshizuku inks have a similar pH to Sailor inks. I grabbed some Fuyu-gaki and Ama-iro and mixed them. Sure enough, precipitate. I also tried some Iroshizuku Ama-iro with Sailor Grenade and got precipitate.

mixing fountain pen inks iroshizuku ink

This mix of Iroshizuku Fuyu-gaki and Ama-iro produced solids, and also an unatractive color.

Finally, I wanted to try a more acidic ink with a more basic ink. It turns out most Montblanc inks are acidic, so I mixed some Corn Poppy Red (pH 5) with Grenade. While it wasn’t as obvious, I’m still going to say that I got precipitate.

mixing fountain pen inks corn poppy red

This mix of Sailor Grenade and Montblanc Corn Poppy Red has a few solids.

After seeing so many combinations that formed precipitate in a row, I wanted to make sure that somehow the container that I was mixing inks in hadn’t been contaminated. I went back to one of my early mixes that did not form a precipitate, Sailor Grenade and Blackstone Lemur Lime, and mixed it up. Once again, no precipitate. Now I could be sure that particular combinations did indeed mix well while others mixed with bad results.

mixing fountain pen inks no solids

This is a mix of Sailor Grenade and Blackstone Lemur Lime that did not produce precipitates.

At this point I decided to stop. I’m sure I could have spent all day mixing inks from different manufacturers, but after seeing how easy it is to get a precipitate, I realized that mixing inks is something that I’m going to avoid. I didn’t need any more proof that it’s a bad idea.


I figured that I’d have to spend a lot of time and mix a lot of inks to see any type of solids, but it turns out it happened fairly quickly and much more often than I would have predicted. Even more surprisingly, inks from the same manufacturer didn’t mix well. I thought for sure that mixing two Sailor inks or two Pilot inks would be safe, but it turns out it’s not a good idea.

One good question to ask is whether any of these mixtures would actually clog a fountain pen? I certainly don’t plan on trying any of them in my pens. I did find a few nice color combinations, but none that are worth ruining a pen over. Still, the actual solids that formed were small. At the most extreme, I was expecting something like cottage cheese, but the reality is far from that. Still, it doesn’t take much to clog a fountain pen and I’m sure that some of these mixtures would do the job.

The bottom line and main takeaway from this is don’t mix fountain pen inks. It may be fun to create new and unique colors, but the risk isn’t worth the reward. Furthermore, at a minimum you should always flush your pen with clean water before filling it with a new ink color. I would definitely recommend fully cleaning your pen, but if you can’t, a flush should be enough to prevent any pen-clogging solids from forming.

Comments 29

  1. John, I understand your caution. Not only that – in many circumstances it’s pointless. Take Diamine with 100 inks all the same price. If you want a dark brown then buy it rather than mixing. Risky and pointless.
    However, I have two bottles of Quink Red. It’s not a favourable colour for me. Well, to be blunt I never use red. I have Quink blue and Blue-Black which are not special to me but I use them just to use them up. Last month I started mixing Red with either of the Blues and produced some nice purples and mauves, all of which I shall use. A redish blue or a bluish red – nice colours.
    So although I understand your caution I can vouch that Quink Red, Blue and Blue-Black mix without problem. I remember telling you that when I married I had the wife’s old inks added to my collection, but the red was a pinch of red powder in a bottle. It had dried up completely. I added water and became Quink ink again.At last I have a use for Red. I re-constituted it 25 years ago and didn’t use it once until now.

    1. Post

      Noel, I totally agree that there are so many colors out there that there’s no need to mix inks… just find a color you like and buy it!

      That’s not a bad idea if you have inks you don’t want to use. I can see that many people wouldn’t use a color like red, so might as well mix in a bit of blue and get a purple. I think if you know the risks and it’s done with caution, might as well give it a try.

  2. Timely article for me to read because I was recently looking at making my own colours. However I’ve just purchased the 9 colours of the Platinum Mix-Free inks so that I can do just that without worrying about whether they mix.

    1. Post
  3. I’ve tried mixing inks before and created this color I quite like, it’s like a dark teal, a bit darker than Lamy Amazonite, but it wrote really dry for some reason. Not sure if it was caused by precipitates clogging up the feed but I didn’t notice any.

    This might sound a bit stupid (and pointless) but you could try decanting the ink to remove the precipitate, then leave it overnight or so to see if more precipitate forms. If the chemical reaction is finished or reached equilibrium, it shouldn’t precipitate anymore so it should be safe to ink up. But then again, it’s probably not worth the hassle as the ink properties would’ve changed and you won’t really know how the ink will behave.

    1. Post

      It could have been some precipitates making it write dry or maybe just some chemistry? Too bad if you really liked the color!

      I considered trying to mix some inks and see if I could get the solids to settle out, but from what I could tell the solids were so small that some would likely stay suspended in the solution. This was about the time I realized I just wouldn’t mix inks and not worry about it. 🙂

  4. A year or two ago I had great fun making ink from food colouring. Not the thin watery type, but the gel type. you can make a pint for £1, but small amounts is best. It would take years to use a pint, by which time it would be mouldy.
    It’s a cheap way to have fun mixing colours, and I had no precipitation or clogged pens. I didn’t test pH, but it has to be weak in order to be edible. You won’t get a good black this way, but lovely green blue red combinations are possible.

    1. Post

      Ooh, that sounds like it could be fun, but personally I don’t think I’d put it in my pens. Maybe good to try out in a dip pen instead? Was there a recipe you found somewhere or just decide to give it a try?

  5. I found a reference to it on the net. My wife had “out of date” food colourings. She’s quite legalistic about those dates, so rather than throw them away I tried making ink. It’s simply a matter of thinning it with water. It worked with my glass dip pens so I tried it my rubbished fountain pens – usually they’re cheap Jinhao with a wonderful nib and bad plastic that cracks or breaks. I had no trouble. If you have a $1 pen lying around then try it.

  6. Sorry, John, I should have mentioned that a drop of gelatine should be added if you don’t want the nib to dry out.
    Many people will think it’s silly to concoct ink in the kitchen, but it should be borne in mind that people were making ink centuries before factories existed. Factories simply copied and monetised, and eventually improved, home-made ink.
    I knew a guy years ago who wouldn’t eat home-made jam because his mother, who couldn’t cook, had convinced him that it was poor people’s attempt to copy the real thing – shop jam. A common fallacy.

    1. Post

      Good to know. I may give it a shot if I have a “sacrificial” pen laying around. And so true that most things we use today were made by hand/at home years before they were mass-produced. That’s a funny story about home-made jam! I can’t imagine…

  7. Thanks again for your research.
    I would like to write with a fountain pen on black paper. So, I’m trying out mixtures with white De Atrementis … and to start with I’m only mixing with other inks from DA. And the document inks are made to be mixed apparently. I started with fuchsia and white and that worked.Now I have some mixing bottles I’ll try some more.

    The white ink separates however so only small mixes will be made and only a small amount loaded into the pen.

    1. Post

      Sounds like quite an undertaking! I’ve never tried the De Atrementis white ink, but think it would be a weird experience to write on black paper. Best of luck!

  8. Have you perhaps tried diluting the precipitates to see if they dissolve? My reasoning is that they are merely salts that have gone out of solution because the mixture has gone over saturation for the temperature, given that even when you mixed 2 alkaline solutions together and they still formed, that tells me that it isn’t from a reaction. It is possible that both inks contain salts that when mixed together would cause it to be over the saturation limit and precipitate. Although dilution would be difficult since it is not known what the solvents in the ink are exactly.

    1. Post

      Honestly, I haven’t. I’m sure it would be possible to somehow remove the solids, but just having them form was enough for me to know that mixing inks isn’t something I want to mess with.

    1. Post

      Great idea, Smiley, and truly the safest option. Still, many people want to use the colors that they create in a fountain pen, so knowing the risks is part of the process.

  9. Yes, I use dip pens when I make ink, As with food colouring, dip pens are often the better. choice.
    I also use fountain pens that cost less than £1 / $1.

  10. Sometimes an ink is not exactly the hue I had desired and I’ll use another ink of the same brand to change that hue. I have a background in chemistry (and a little bit of art), but have no idea what chemicals go into the formulation of various brands of ink. I do think it would be relatively safe within the same brand (because they’re likely to always use the same base ingredients for their entire line) as long as one watches for precipitate.

    Indeed–I’ve seen precipitate just from adding water to an ink in an attempt to desaturate the hue and increase shading. However that was a waterproof ink that is likely made with acrylic. That said, a good pen flush cured the pen that I foolishly put that ink into (only later looking more closely at the sample bottle I had mixed it in.) Side note–it’s smarter to use distilled than tap water due to the many dissolved solids in tap water and probably don’t add water to waterproof inks.

    I don’t worry so much because I’m not into fountain pens for prestige–I’m in it for utility and for pleasure in the writing process–and therefore rarely spend more than $30 on a pen. In fact my very favorite pens (and most reliable) are student pens from Germany such as the Pelikan Twist (available if you look for less than $15). The Lamy Safari is probably my very favorite pen of all time.

    I hand write a lot because I’m an author (sometimes free-writing by hand can break writer’s block) and because I’m forgetful and need to make myself reminder notes all day long. The pleasure in the writing–watching an ink shade, for example–can help break me out of a funk!

    I wish to thank you sincerely for the resource of this website. I have found so much valuable info here and I sure wish I’d found you sooner. I will have many lovely mornings sipping coffee and reading your posts in the future. You’ve opened my eyes to new papers, new inks, and a ton of good information that can only come from experience and sensible and objective assessment.

    1. Post

      Thank you for this great information, Jen. I must say that I figured inks from the same brand would be safe to mix, but in my experiments that wasn’t always the case. It’s also very nice to use inexpensive pens for experiments in case something goes awry, and since some pens like the Lamy Safari are great writers regardless of how much they cost, why not?

      I’m so glad that you enjoy this site and what it has to offer. I hope that you have some great mornings with coffee and pens!

  11. I’ve used Lamy inks to mix, and I don’t think there were precipitates. But usually, you would have to mix colors of the same brand to get the result you want. I have 3 primary colors from Lamy and a green. I’ve mixed teals and purples so far.

    1. Post
  12. I only mix those inks which were poor choices. In other words they would have been binned.
    I have not had a failure yet. Indeed I a using three different rescued inks that are a total delight in behavious and colour.

    Some basic rules I adhere to:
    I never attempt to shift the colour very far. So no making green from a blue and yellow.
    I never blend particulate inks such as pigments.
    I never blend permanent / archival or water resistant inks. They have a lot of complex chemistry in them.

    The remaining inks are aniline dye based and in my experience rather tolerant of each other. (I noted your Grenade/ Corn Poppy result as a caution to myself.

    There are two or three major arylene dye manufacturers in the world so I don’t limit myself only mixing within a brand. Different brands are likely using the same sources.

    Lastly I mix ink in a using urine sample bottle using only a few ml of ink and a syringe with a blunt needle to add and measure the inks being mixed. After each incremental addition a nib is dipped and the result tested before proceeding.

    Some basic things to do with an unappreciated ink.

    If it’s too bright add a few drops of Black ink. It takes the brightness off really well without changing the underlying colour.

    If an ink is too dark I mix water in, in increments as above, never more than about 20%. This lightens the ink and can produce an ink with good shading too. Notice I say lighten, not brighten. Quite a number of modern inks are highly saturated. There is so much dye in them they can become dark and even a little ink on the page is saturated. Which I think is why they don’t give shading.

    To brighten an ink I would mix a brighter ink of a similar colour. So for example Diamine Ultra Green mixed with Diamine Woodland Green produces something akin to Sherwood Green but a shade brighter. A few drop of black ink makes it a perfect math for Sherwood Green, but I preferred the slightly brighter version.

    It’s not for everyone, but I have saved quite a few inks from the bin in this way along with improving my understating and appreciation of colour, shade and tone.

    I hope this is useful to folk.

    1. Post

      Thank you for so much information, Kevin! It sounds like you have quite a bit of experience with ink mixing. I’ve definitely dabbled but haven’t really had extensive experience. Thanks for the insights into subtly changing the colors of inks and even coming up with your perfect mix!

  13. Another example might be useful Please delete this if it is too much.

    I had a bottle of Sailor Jentle Blue growing old in my drawer. A great ink, but the colour just wasn’t to my taste. So I looked around for similar colours I liked a lot. Pilot Shikiore Blue Black came to mind.

    I had a sample of that so I inked a pen up with it.

    Next I needed to move the Sailor Blue ink towards a blue black tone. I titrated Sailor Jentle black into it until the tone was correct. But the result was a Blue Black to the grey side of that family. Similar to many other Blue Blacks around.

    So, next I titrated in a strong blue, again it didn’t need much and it was done in small steps. When tested the end result I couldn’t detect any difference between it and Sailor Shikiore Blue Black. It even had Pilots superb shading qualities.

    This was a double bonus. Sailor Shikiore is not available in the UK and it’s expensive to buy from overseas. Second I had rescued an ink I would never use.

    Private Reserve Tanzenite was dark and dull. I merely titrated it with water, I think about 25% and then Diamine Violet to push it across to the Violet side a little. It still stains BTW! This is my favourite Tanzenite colour ink. Though with a bright light shone in my eyes and severe bodily threats I would admit to preferring Monteverde’s offering.

    Again, hoping this is of some interest.

    Be well.

  14. Pingback: Can You Mix Fountain Pen Inks? –

    1. Post

      I’m not really sure. I’d suggest mixing a small amount and then seeing if it looks like there are any solids. It will also give you an idea of what color you’ll end up with.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.