Evaluating Commercial Dyes For Ink

June 29, 2017

This information is provided as a starting place for those interested in developing their own fountain pen ink. I do not claim my research is exhaustive but merely a starting point for those who wish to experiment. Please note that I have not been at this long enough to provide any long term test results. I make no representation that the items indicated below are safe for your pen (or for you). Consult the applicable MSDS data sheets which are available if you search the name of the product on the web. For all items, but particularly if you handle powders, observe all safety recommendations regarding ventilation, breathing and eye protection,using gloves and avoiding skin exposure and inhalation. If you have any concerns – don't do it. I have not had any problems, but everyone is different and anyone can have a sensitivity or an allergic reaction to a given product. I do not encourage anyone to handle the dye powders discussed below unless you have some experience in handling chemicals – if you stick with the three primary colors in the form of liquid food coloring, you have plenty of room for experimentation – although there are warnings available on the web concerning the dyes used in food coloring and you should consult these and make up your own mind if you want to proceed.

Now down to the business at hand. I backed into this project when I wanted to breath life back into a very nice Mont Blanc 146 my wife had given me years ago. I had stopped using it due to concern that in the rush of day to day business it would get lost, dropped, etc. I did some research on the web as to what to do and not do and fortunately the pen came back into working order with a little patience and relatively minor attention. In getting more background on fountain pens, I was somewhat put off at the cost of ink. I think many commercial inks are somewhat justifiably priced due to the fact that it is a very niche market and packaging and distribution costs are relatively higher given the low volume of product sold. The fact remains, however, that the basic cost of the materials did not seem to be consistent with much retail pricing. Having been a chemistry major into my junior year of college, my curiosity got the better of me and I began looking for information on fountain pen ink formulation.

Many sources generally refer to ink as a weak (1-7%) aqueous (water based) solution of dye and water. My favorite reference was to one group of industrial chemists from a dye manufacturer who refer to ink as “dirty water.” My initial thought was to try a reactive dye (procion MX type) which is readily available at art stores. Further, research, however, indicates that procion MX types of reactive dye are actually too reactive. In solution they hydrolyze (react with the water) in a short time, neutralizing the two reactive points on the molecule that allow them to create a strong bond. They don't lose their color, so they may still be useful as non-waterproof dyes, but since their primary benefit was their reactivity and strong waterproof bonding, I moved on to other dyes. Another possibility was vinyl sulfon dye. These are also reactive, but have only one bonding point rather than two so they do not lose their effectiveness as quickly in water solutions and have a better shelf life, sometimes estimated at one to two years. This would be more practical for an ink. They are usually recommended to use with heat to set the dye, but there is at least one reference I found which claims that time is a substitute for heat and some degree of bonding occurs in a 24-48 hour period after application. I won't bore you with a discussion of thermodynamics in chemical reactions, but this result makes sense. Chemical reactions are based on energy – heat provides energy – so many reactions continue to occur at lower temperatures, just more slowly.

At the same time, I was pursuing a line of inquiry as to what dyes were used by ink manufacturers. There is not much information I could find. This makes sense, since each maufacturer would consider their dyes and additives proprietary and would not want to disclose them publically. I did find one reference which relied on an encyclopedia of industrial chemistry to indicate that blue inks were commonly based on triarylmethane dyes. This set me looking for sources of these dyes. There are several scientific supply houses which handle these dyes in powder or liquid format, but they are scientific grade products which seem relatively expensive ($1-$5 per gram). For ink, I see no reason why you would need reagent grade dye and a commercial grade should be lower in cost. Approaching the problem from the point of view of what other commercial uses are there for triarylmethane dyes, I came across what is the simplest solution I have found so far. Blue food coloring often uses FD&C Blue 1 (also known as E133 in Europe and , in the UK, Food Blue #2). This is the dye commercially produced as Brilliant Blue FCF, which is – wait for it – a triarylmethane dye.

One problem is that many food coloring products include sugars and gums. These might be diluted sufficiently in an ink preparation so as not to cause a problem, but they clearly have the risk of (sorry) gumming up the works of a fountain pen. However, there are very basic food dyes out there that are not gussied up with the added ingredients. My initial experiments have been made with Smart & Final Blue Food Color. The ingredients are listed as water, Blue 1, citric acid and sodium benzoate. The citric acid is problematic from the point of view of rotting your pen parts on prolonged exposure, but my initial thought is that the sodium benzoate is fine, since you would want a preservative of some sort in the ink anyway to prevent mold growth. Further research yielded two results: (1) we don't know the concentration of citric acid, but typical citric acid solutions have a pH between 2 and 3, and; (2) several common commercial inks have been measured to have a pH between 2 and 3. While there is a lot of speculation about the effect of inks with low pH, there does not seem to be any stream of complaints by users that low pH inks actually corroded their pens. The only claim of a corroded nib I found was on the site of a retailer trying to sell gold nibs. I think the best common sense cautionary statement I saw was that, just to be safe, you shouldn't use low pH ink in classic, vintage or collectable pens.

Under the heading of it is better to be lucky than good, I thought the odds were in favor of the basic food color being too weak or too strong for use as an ink. I thought I would have to dilute or reduce the product to get a color value consistent with use as an ink. Still, I needed a baseline, so I inked up a dip pen with the food color and started to write on a piece of copy paper (I didn't want high quality paper masking problems with feathering or bleed through). Result – beautiful mid-blue text with no excessive feathering or bleed through. It dried too quickly for my taste, so I added a drop of glycerine (1 drop in my 5 ml test sample = 20 drops per 100 ml or roughly 1% glycerine). I let the dip pen sit uncapped and wrote samples at 1,2 and 5 minutes with no problem. I then re-inked the pen and let it sit with attempts to write at 10 minutes and 20 minutes. At 10 minutes one short stroke was necessary to get the pen writing again with no other problems but at 20 minutes the ink had dried and the pen would not write even after several short strokes to get it going. The ink dries on the page between 5 and 10 seconds but is not waterproof (this doesn't bother me since many commercial inks are not either). For comparison, I inked the same pen with a well known commercial ink and it refused to write after sitting for 10 minutes.

I have no intention of using my Mont Blanc as a test bed. I have some Jinhao 992s on the way from China which may wind up sacrificing their lives in the interest of science ( or at least curiosity). I intend to ink one up with the 1% glycerine blue and see how it performs in a long term test. The forum moderator has posted a request that names be assigned to inks, so I propose FC Blue – since it is food color based.

One final experiment was to try to create a green ink. There is some discussion in a web reference about using tartrazine (a yellow azo synthetic dye) with Brilliant Blue FCF to create greens. Smart & Final Lemon Yellow Food Color has the same ingredients as their blue except it uses FD&C Yellow 5 rather than Blue 1. You guessed it – Yellow 5 is tartrazine. 6 parts blue to one part yellow (and 1% glycerine) gives a nice medium green. I test fired it with a dip pen on 60# Neenah Astroparche text (roughly equivalent to a 24# bond weight) with no significant feathering and no bleed through.

I hope this information provides a place to start for those interested in formulating their own fountain pen ink. It is preliminary, but attempts to use commercial dyes similar to those actually used by ink manufacturers. I don't have a pH meter, so someone out there with access to one could check these solutions and perhaps try some additives to give a neutral pH if they feel this to be a concern. I will be doing longer term tests when I get the Jinhaos and checking for flow and drying problems. I also will be doing some color blending when I get some red (FD&C 40) food color (out of stock when I got the other 2). Cost of the food color was nominal ($2.50 for 16 ozs.) and the 99.5% glycerine was $4-5 at Walmart. Nothing is meant to suggest that the commercial inks available are not worth their price. Paying people to formulate and test different dyes and additives to improve ink performance or create new colors is not a minor investment given a relatively small market. However, not everyone can afford $10 to $30 (or more) per bottle and there are those of us who like to get to grips with the real underlying dynamics of the products we use. I hope this helps. Go make some ink.

July 4, 2017

UPDATE - Received some Jinhao 992s and have now inked one up with the FP Blue to use as a test bed and see how it performs in a fountain pen. Initial performance is good. The pen wrote immediately and flow seems good. There is no sign of any flow issues and delivery is smooth and constant. The pen is not too wet but there is plenty of lubrication for writing. I will be maintaining this ink in the pen and using it on a gradually decreasing schedule to see if there are issues with the ink drying out over increasing time periods. Pen will be stored flat, so I do not anticipate drying issues, but no way to know until it is tested.

July 4, 2017

Keep up the great work! Interesting stuff... I'll be taking a closer look at ingredients next time I'm sniffing around the catering supply outlets.

July 16, 2017

This is interesting - please, let us know your results!

July 20, 2017

Update #2

I have now left a Jinhao 992 inked with FC Blue sitting unused (capped) for intervals of 1,2,4 and 6 days. In all cases the pen wrote immediately with no problems. I will continue with longer term tests, but, so far, the results seem to indicate a very usable ink.

On other fronts, I located some red food color with no additives beyond citric acid and sodium benzoate (the same as the blue). It uses FD&C Red #40, commercially known as Allura Red AC and also identified by various agencies as Food Red 17 and E129. This is an azo type of dye. Note that this is not Eosin which is identified in the literature as a typical basis for red ink. The version I got was house brand Smart & Final and was labeled as double strength. Cost was $4.99 for 16 oz. Out of the bottle, it was quite scratchy and clearly needed more lubrication. It also dried in the pen after only a few minutes. 1% glycerine (1 drop per 5 ml) was improved but still scratchy when writing. 2% glycerine seems better and the 2% glycerine solution is the basis of my longer term drying tests. My color goal had been a dark red (I am not fond of bright reds except for accounting or correction purposes and, for economic reasons, I can't say I am fond of it in accounting). I had intended to add blue as necessary to darken a pure red, but straight out of the bottle the FD&C #40 gives a deep red drying quickly to a burgundy color on the page. For my purposes, I am quite happy with the color as is. For drying tests, so far I have left it unused and capped (in a Jinhao 992) overnight and for 2 days and in both cases the pen wrote immediately with no problems. If you try it and would like a little more lubrication, I suspect you could add another drop of glycerine per 5 ml (3% glycerine) with no particular problem. I tried diluting it 2:1 and 3:1 with distilled water and you get a lighter red but with brownish overtones, not a pure red. I tried various mixes and dilutions with the FD&C Blue #1 food color and it gives a brown full strength and very diluted is kind of a dull mauve, not a true purple (think WW1 German underwing biplane camouflage).

Last, and probably least, I did look at a Procion MX type of dye. As noted in an earlier post, this hydrolyzes in water, losing its ability to bond with cellulose. I had some red dye sitting around from another project. It had completely hydrolzed due to age and had thrown a sediment. I tapped some off the top to check color and with 1% glycerine it makes a light red ink. However, due to the sediment it throws, I would never use this in a fountain pen. I guess you could filter it after letting it sit for a long time to be sure it had finished throwing sediment, but to my eye, the color wasn't interesting enough to go to that much trouble.

For further work I intend to continue longer term testing of the red for problems drying out with disuse. I also have located a couple possible sources for Eosin. I would like to see what kind of a red this makes up. Apparently, there are two versions Eosin Y and Eosin B. Some suppliers limit sale to institutions, so it may be a problem to get, but I will note any progress in a future update.

July 26, 2017

UPDATE #3

FC Blue - 10 days unused, capped in a Jinhao 992, writes with no hesitation.

FC Red - Based on the slight hesitation to start after 6 days capped, I am going to try 3% glycerin. 2% is not bad, but adding a little may make it something where you don't have to worry about it drying on the pen.

New - I ordered and received 2 - 1 oz. bottles of Eosin Y ($4.50 each) from a scientific educational supply house. These are 1% aqueous (water based) solutions of the dye. There are also alcohol based solutions, so if you order it be sure you are getting the water based version. With shipping, this costs about as much as a lower priced commercial ink, so unless you use a lot of red or purple, the advantage is flexibility to mix a custom color, not necessarily price. Out of the bottle with 1% glycerin added, it comes off the pen a little orange but dries to a fairly bright pink. Presumably, you could evaporate it to get a more concentrated red, but I went a different route.

My first goal was a purple (my wife likes purple). By gradually adding the blue food color (FD&C Blue 1) I got to a nice medium purple at 5 ml of Eosin Y solution and 1/2 ml of blue food color. This is roughly 10% blue added to whatever volume of Eosin Y you start with. It seems to need about 4% glycerin to keep from drying to quickly on the pen, so I will be looking at how it holds up capped. Overnight, it shows no sign of precipitating any solids from the mix, so I will be putting it in a Jinhao for longer term testing.

To get a red, I started gradually adding the red food color (FD&C 40) which is labeled as double strength. To my eye, the best straight red resulted from a 2:1 mixture of Eosin Y to red food color, diluted with water to 2/3 original mix and 1/3 new water. A nice dark red results from a 1:1 mixture of Eosin Y and the double strength red food color. I did not mix any substantial quantity of either of these red mixes, so I have not checked for precipitation of a solid after 24 hours. I will be doing this next, probably with the 50/50 mix.

July 27, 2017

Please, if you can, add some pics of your writing tests. You have my attention ...... very interested in your tests!

August 1, 2017

UPDATE #4

Per request, I swatched some of the colors I have prepared as described in prior posts. These were done on the back of index cards. The swatch is made with a Q-tip and the name written in the same ink. (You have to put up with the bad handwriting, I suffer from essential tremor.) I scanned the cards into both .jpg and .pdf format to see which looked closer to the actual appearance of the cards. Neither is exact on my monitor, but the .jpg was closer, so that is what I will attempt to attach to this post. The only new color is the olive green, which I spent some time working on yesterday, trying approximately 20 mix variations. I also swatched the Eosin Y by itself, just so folks know what it looks like (and in case they like pink ink). Overall, the scan shows the colors a little brighter and more saturated than they appear on the cards and the olive green is a touch greener in real life. Otherwise, the colors are fairly close (at least on my monitor).

January 11, 2018

Thanks for posting this. Im working from dye powders from a number of dye classes because they were in danger of being thrown out at work. Im most pleased to get guidance on glycerine amounts. Im also interested in the food color angle too.