fountain pen ink chromatography samples

What Is Fountain Pen Ink Chromatography?

John BosleyMiscellaneous 19 Comments

You may have noticed that when fountain pen ink gets wet, it can sometimes separate out into different colors. This might happen when you’re cleaning your pens or just playing with some ink and water on paper. The reason this happens is because ink can be made up of different base colors. For example, green ink might consist of both yellow and blue dyes. In this article I want to explore fountain pen ink chromatography to get a better understanding of the colors that make up different inks.

What Is Fountain Pen Ink Chromatography?

Fountain pen ink chromatography is when you use liquid and paper to separate out the components of another liquid, which in this case is fountain pen ink. The reason this happens is that as the ink moves through the paper, the different dyes that are in it move at different speeds, which causes them to separate and become visible. Here’s an example of how it looks compared to a writing sample with the same ink:

fountain pen ink chromatography comparison

You can see that the ink color is much different than the chromatography.

This might look familiar if you took a high school chemistry class. In this example, I’ve used chromatography paper and water to separate out the dyes in the ink. You can see that while the ink looks green on paper, it is actually made up of two different colors… blue and yellow. This is much more common in more complex colors. For simple colors that are much more “pure”, like ordinary reds and blues, you won’t typically see any color separation (although you might be surprised at how often you’ll see colors that you didn’t expect to see).

fountain pen ink chromatography blue ink

This blue ink doesn’t have any additional colors in it.

Trying Chromatography Yourself

So do you need special paper to try chromatography for yourself? Fortunately, you don’t! Chromatography paper just makes it easier to do. If you don’t want to buy any, you can use a coffee filter or a paper towel instead.

fountain pen ink chromatography paper towel

A paper towel (left) or coffee filter (middle) can achieve a similar result to chromatography paper (right).

You can also achieve a similar effect using watercolor paper. This has become very popular with many fountain pen users lately. Artist Nick Stewart has been making amazing inky “landscapes” using watercolor paper, water and ink. This process also allows the dyes in the ink to separate and become visible. Many pen and ink enthusiasts, myself included, have taken inspiration from this process to play with water and ink and see what happens.

fountain pen ink chromatography watercolor paper

Pelkan Smoky Quartz ink chromatography on watercolor paper

Why Chromatography Matters

I keep an ink journal of all of my inks and for each entry I also do a chromatography strip. When two colors look very similar but I like one more than another, looking at what colors make up the ink can help me see the color difference between the two. While it might not be extremely helpful when buying inks, it has helped me to be able to start seeing the differences between similar ink colors.

fountain pen ink chromatography similar inks

These two inks look similar on paper, but you can see their chromatography has different color distribution.

Chromatography can also be a fun science experiment you can do with your kids. Not only do they get to play with ink and water, but they also get to learn about color combinations and see that ink is more than just colored water.

How To Do Fountain Pen Ink Chromatography

To start, you’ll want to put a drop of ink on the paper you want to use. In order to get the most accurate results, I’d suggest a drop straight from the bottle. While you can simply touch your pen to the paper and let it suck out a bit of ink, I’ve done this in the past and found that my pen wasn’t as clean as I thought and had a bit of old ink end up in my results, which defeats the purpose of doing it in the first place. In order for chromatography to work, water has to be pulled through the ink sample, but the paper will pull the water via capillary action, which happens naturally

When I use the chromatography strips, I use a binder clip to attach the paper (which is already inked) to a popsicle stick. I then put the stick across the top of a glass with just enough water in the bottom so that it touches the paper. Remember, you want the water to be pulled through the ink sample, so don’t completely submerge the paper. I like to draw a line across the paper where I put the drop just to see how much progress the ink is making. To do this I use a Sharpie, which isn’t affected by the water and won’t alter the results. Once the paper is in the water, I wait for anywhere from 5-15 minutes, depending on how the ink is separating. I usually let the ink get close to the top of the paper, but you should be able to easily see it separating well before that.

fountain pen ink chromatography setup

The colors will start to separate immediately…

fountain pen ink chromatography color separation

Make sure to wait so that all of the colors separate out.

If you use a paper towel or coffee filter you can use the same process, but you can also do it laying flat. Simply add a drop or two of water to the ink sample. This will cause the ink to spread out in a radial pattern, but the results won’t be affected. You’ll probably notice that the results aren’t nearly as precise as those using chromatography strips. This is because both paper towels and coffee filters soak up liquid very quickly, while chromatography paper is specially designed so that liquid is absorbed slowly and the dyes separate out much more uniformly.

fountain pen ink chromatography coffee filter

You can see the results are much better with the chromatography paper than with the paper towel or coffee filter.

Final Thoughts

If you’ve never tried fountain pen ink chromatography (or even heard of it), it can definitely be a fun experiment to try. While not all inks will be exciting, some will surprise you with the number of different colors that unfold from a single drop. Of course, this isn’t something that’s going to improve your handwriting or make the pens you buy any less expensive. It’s purely something fun and educational to do. I’m sure that if you give it a try you’ll be pleasantly surprised by the results and will enjoy the process.

If you’re interested in trying out chromatography for yourself but don’t know where to get the paper, I get mine on Amazon. If you have a science supply store near you, they should also have it.

Comments 19

  1. John – I searched for chromatography paper on Amazon (UK) and found only General Purpose Filter Paper and Blotting paper. Will they be good enough? Your Amazon link doesn’t point to anything.

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      Noel, the blotting paper definitely won’t work, as it’s made to absorb liquid very quickly. The filter paper should be similar to a coffee filter. I updated the link, so it should work now. Thanks for letting me know!

  2. This is so cool – and love the idea of an ink journal. Do you have a bound notebook and particular paper you use for it? May need to start one. Thanks for a great read (much less stressful than reading the news in the morning).

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      Amelia, I use a Tomoe River notebook for my ink journal. It’s a great way to see what inks I have and how they look when used with particular pens. I’ll write a post about it to give you a better idea of what it’s like. Thanks for reading!

      1. Would you ever consider and in depth look at your ink journal? I’m trying to start one and it’s so confusing. I don’t see how people in youttube videos can make a 2 ml sample go that far in 5 different notebooks and full swatches on watercolor paper. AND do chromatography. There’s no way a 2 ml sample can do all that. Writing yes, but not Ink reviews.

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  3. Great article. Used link from Ink Journal. Will order strips from Amazon. Have been using coffee filter paper. Inconsistent results. Thanks for sharing.

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  4. I love this John! Having been a laboratory scientist for 35 years I have actually done chromatography for drug screens. I have always liked the “magic” so you can bet I am going to burn through a lot of coffee filters! Thanks for the chemistry love!

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  5. Thank you for creating and sharing this beautiful, peaceful, creative project, as well as sharing the work of others. I know the writing and photographing etc. takes thought and effort and it is so soothing to see something that engages one’s curiousity and creativity right now.

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  6. Many thanks for explaining this process. I’ve also been amazed at Nick’s work and a number of ink reviewers who have used chromatography as part of their reviews but this is the first time I’ve seen anyone describe how to do it. I love how the ink separates out on the Col-o-Dex paper I have so this was something I was wondering about, but hadn’t got round to exploring. Now I will.

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      Many thanks for reading, Cathy! It’s a fun process to experiment with and, as you’ve found out with the Col-o-Dex paper, you don’t necessarily need special equipment to do it. Have fun exploring!

  7. They would not ship my Amazon order (CHROM-50-6X75 – Chromatography Paper Strips from PRECISION LABORATORIES SE) to me as they can only ship a business address due to a feature of the paper, poisonous I think. I didn’t have one so they cancelled ordered. How did you order yours?

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      That’s really strange, Chris. I’ve never had any issues ordering them and I live at a residential address. I haven’t tried to order those particular strips, but it doesn’t say anywhere in their shipping policies that they won’t ship to a residential address. The paper isn’t poisonous as far as I know. You might try ordering a different item and hopefully you’ll have better luck.

  8. It was interesting when you talked about how chromatography can help you determine what makes up two similar-looking colors. Now that I think about it, I’d be curious to learn if high-performance chromatography can be used to identify materials in a scientific context. Your article explained chromatography in a way that was fun to learn about, so thanks for taking the time to discuss it!

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      Thanks for giving it a read, Rebecca. I’m sure that “real” chromatography would be able to give some really interesting and useful information. I’d love to learn more about which dyes are used in inks.

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