is mixing fountain pen inks dangerous

How Dangerous Is Mixing Fountain Pen Inks?

John Bosley Fountain Pen Ink 15 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.

Conclusions

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 15

  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.

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      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.

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  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.

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      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.

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      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.

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      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.

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      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.

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      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.

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