Diamine ink is great. The range of colours is amazing and they generally have very few flaws, behaving nicely in most pens with minimal bleed and relatively fast dry times. They also do a range of 'Deep Dark' inks for Cult Pens in the UK, more on these in the future.

Beyond the great colours the fact that you can purchase a 30ml bottle of ink at a time for just £2.35 each (~$3.35 USD) gives you an opportunity to try more colours, getting through 80ml of any one ink before it goes off is quite a challenge. However there is a big, or in this case little, problem with the bottles. The neck on the bottle is very small and a lot of my pens just didn't fit.

At this point a closer look was taken at a small collection of fountain pens and a standard 30ml Diamine bottle that had been procured recently. A vernier caliper was used to measure the diameter of almost all of the pens in two places. The first position on the pen was the grip section nearest to the nib. The second measurement was taken 10mm above the grip section on the barrel. The data can be seen in the two graphs (yikes, mathematics!) below:

Diameters of the pen collection

The Diamine bottle has an internal diameter of 12.3mm (bottle to bottle variation unknown), however you probably want around 1mm each side to ensure you don't get too much ink onto the pen during filling. From the left hand graph you can see that all of the pens in the measured collection will fit into the bottle somewhat, however approximately 25% of the pens will not have a satisfactory clearance at all (not enough to get the nib into the ink properly). The problem is even worse beyond the first fill, to get to the bottom of the ink bottle you need a lot of the pen through the hole and looking at the right hand graph it is clear to see that a most of the pens just won't fit.

A Range of bottles were tested as part of the United Inkdom meta review with various sizes, shapes and materials.

Do They Leak? An obvious check but very necessary, luckily all showed no signs of leaking even during vigorous shaking or when left upside down.

Do Pens Fit? At this point a very large pen was selected to test this out, a Fosfor Bangalore. The plastic bottle with a 20mm neck just wasn't wide enough to enable the pen to fit right to the bottom, a lot better than the Diamine bottle but not as good as the rest. The Atlas bottle was a bit small, the pen fit but only just and would probably pick up quite a bit of ink on the way back out. If your collection is generally smaller than this large diameter pen then this bottle could still be a good option. All other pens fit easily and without making contact with the neck walls.

Do pens fit?

What about Filling? The Mini glass jar is very short and wide, so getting the last ink out of the bottom could be a challenge. The Sterilin bottle has a conical bottom internally which means that of all the bottles you will probably get the most out of this one before having to resort to a syringe. It is however a lot taller and narrower so could be unstable whilst filling, with ink that would turn messy very quickly.

Filling a Pen

Do they break? Glass is obviously much more likely to break when dropped from a height, so if you are travelling then you may prefer plastic. All the glass jars are well made and survived a drop off a dining room table onto wooden floors, the vacuum cleaner was ready just in case.

How do they look? Most of the bottles are pretty simple in appearance, which for this price level is expected. Premium inks come in premium bottles, it would not be a surprise if in most cases the major component cost was actually the bottle rather than the contents. The Atlas jar is probably the best looking of them all but this is very subjective.

Any other features? The Sirop bottle comes with an amber glass option, which is actually cheaper than the clear glass version. Whilst the light transmission specifications are not available, from the appearance it looks like it stops a lot of light penetrating the bottle. This could improve the photo stability of the contents, letting your inks last for longer but without proper testing this is only a hypothesis. In a similar vein, the Pharmapac bottle is opaque and so will probably do an even better job.

Conclusions? Based on the cost, practicality and availability of the bottles I would recommend either the Sirop glass bottles or the Pharmapac bottle. Both allow easy access into the container, are stable during filling and are not going to add a lot of cost relative to the cost of the actual ink.

In the end my solution to the 30ml Diamine ink bottle was simple and ended up being applied to all my inks, even those with nice bottles. I love the bottle shape of the Mont Blanc inks, the Rohrer & Klingner pots are nice in their simplicity and the pen rest on the J. Herbin is a nice touch but I love to use the inks more than look at them. I bought some 30ml Sirop Amber glass bottles with plastic lids and using a series of dropper pipettes I transferred the contents of my ink bottles to these new ones.

A range of Diamine Inks in Sirop bottles

I used a Dymo label printer to ensure I can clearly select my ink of choice, currently the label is on the side of the bottle but I will also add one to the top for quick identification. I created an ink colour log in a pocket notebook to aid selection (something my wife helps me with from time to time) when I refill my pens.

Sweet Shop Favourites

Whilst the bottles are round instead of square they still stack together nicely and because of their height I have been able to use an empty sweets tin (previously full of the greats like a good dipdab) to hold them all neatly. They take up less than half the space they did, something my other half appreciates. I have also started adhering to a new rule. I only have 30 of these simple bottles, therefore I am not allowing myself to buy a new ink colour until I finish one of the others (or give them away!). I constantly find new inks and reviews of inks that tempt me to find that perfect colour, but for now I need to get to the bottom of some of the ones I already have.

Where to buy:

  • See here for my recommendations for buying stationery on-line. The Diamine ink pictured was purchased from Cult Pens.
  • Alternative bottles were purchased from Ideon, my favourite was the 30ml Sirop Amber glass bottle with a 28mm neck.


Rafael Rodríguez commented on the United Inkdom blog about a supply of bottles available from Bouteilles et Bocaux, these look very similar to the Pelikan Ink bottles. A great addition to the options available, however definately on the pricey side (~64p) compared to the total cost of the Diamine Ink. Thanks Rafael!