How Long Does A Bottle Of Ink Last Before It Expires?

If you’re like most fountain pen users, you probably have more ink than you can use in a lifetime. And why not? There are so many amazing inks available to use these days it would be nearly impossible to not buy a new bottle once in a while. With so much ink, there is a concern that many people may have. Does ink expire? This leads to other questions. How long can you keep ink before it’s not safe to use? How can you tell if ink has gone bad? These are all things we’ll explore in this article.

What is ink?

It may be helpful to understand what ink is before we go any further. The main ingredient in ink is distilled water. Any color in the ink comes from either dyes or pigments, depending on what kind of ink we’re talking about. There’s more than just water and color in a bottle of ink, though. 

Have you ever noticed that ink is thicker, or more viscous, than water? The next time you’re cleaning your fountain pen, fill it up with water and hold it with the nib facing down. With some pens the water will start dripping out. Thankfully, this doesn’t happen with ink. This is because ink has a surfactant added to it that makes it more viscous and increases surface tension so that it doesn’t leak out of your pen. 

In addition to some other components, ink also contains antimicrobial additives. These are meant to prevent the growth of bacteria that, if they were to get inside your pen, would wreak havoc and potentially infect and damage multiple fountain pens!

Keeping ink bottles in the box they come in helps protect the ink from light.

Does Ink Expire?

The precautions that are taken during manufacturing to ensure ink doesn’t become contaminated with bacteria give it a very long shelf life. Does it have an expiration date? Not really, but eventually it will become unusable. Whether this is due to some sort of contamination or simple evaporation will depend on the conditions in which your ink is stored.

Storage conditions can play a big role in how long a bottle of ink will last. You’ll want to keep ink out of direct sunlight. Ideally, it will be stored in a dark location. If it came with a box, this is a great way to protect it from light. Ink storage temperature should be moderate, so no extreme heat or cold. If you keep it in the living areas of your house, you should be fine (so no attics or garages). 

There are other precautions you can take as well to ensure that ink does not become contaminated. One thing you should always keep in mind is that the more your ink is exposed to external contamination, the more likely it is that it will become contaminated. To minimize risk, any time you’re not using your ink the cap should be on the bottle. This will also help prevent excess evaporation. Avoid putting any ink back into the bottle. If you have extra ink in your pen that you don’t want to use, it should either go down the drain or into a sample vial for later use. 

If you want to save ink from a fountain pen, use a sample vial instead of putting it back into the bottle

This half-full bottle of Iroshizuku Yama-budo was most likely used and has not evaporated.

Using Older Inks And Vintage Ink Bottles

Some people have an interest in using older inks or vintage inks that are no longer produced. Are these still safe to use? The only way to know for sure is to closely inspect the bottle and ink yourself. Modern inks, such as a special edition ink like Lamy Dark Lilac, should be perfectly fine. The bottles seal well and, as long as the ink was stored in a good environment, there’s no reason there should be anything wrong with it. Inks that are in older bottles or are many decades old will need a closer inspection.

Check the Ink Level

The first thing you should look at is how much ink is in a bottle. If it is completely full, you can move to the next step. If it’s not, you need to determine if it was used by the previous owner or if it has evaporated. If you’re not sure, to be on the safe side you should assume that some of the liquid has evaporated. Swab the ink and see if the color looks correct. If the color looks too dark or if it doesn’t look like it should, it’s probably best to avoid that particular bottle of ink.

Check for Solids

One thing you never want in your ink is any type of solid material (with the exception of shimmer particles, of course). Some very old bottles of ink may have a layer on the bottom of the bottle that has settled out of the ink. This is a clogged pen waiting to happen! Furthermore, if this solid is no longer a part of the liquid, the ink color will probably be off. 

Another thing you’ll want to watch for is mold. This is a worst-case scenario. Mold in your ink can quickly spread throughout your pen collection and is difficult if not impossible to treat. Mold can come in two varieties. You may be able to see it through the bottle or floating on the surface of your ink, in which case you know not to use the ink. The other type is called slime in the bottle, or SITB. This can hide inside of the ink and may not be discovered until you pull a slime-covered nib out of your ink bottle. A quick way to check for it in an older bottle of ink is to stir a toothpick through the ink and see if anything sticks to it.

Any ink with sediment in the bottle should not be used in a fountain pen.

Check the Smells

One final test that you should do on any older bottle of ink is to smell it. While ink has a variety of different smells, it should always smell like chemicals or have a fresh smell. Ink that has gone bad will have a musty smell. When in doubt about the smell, it’s best to not use it.

This vintage ink may still be usable, but you would need to check a few things first.

Can You Use Extremely Old Ink?

One reason this subject means so much to me is because I collect vintage fountain pen inks. I have vintage ink bottles dating back to the 1930s that are still usable. Most people are quite surprised to find out that, yes, I actually use them! 

All of the above tests apply with vintage fountain pen ink. I check the ink level, look for solids and give it the smell test. One thing that is impossible to know in a bottle of ink that is over 50 years old is if the reduced ink level is due to evaporation or use by the previous owner. This is where checking the ink color is crucial. Vintage inks were not nearly as saturated as modern inks and bottles did not seal as well, so if the color looks too dark, it has probably evaporated. 

Hopefully this article helps you gain more confidence in using old ink bottles. While ink does not have an expiration date, it will eventually become unusable. Whether this is in 5 years or 50 years depends on how the ink has been stored and used. With proper care, a bottle of fountain pen ink should be safe to use until the very last drop. 


About the Author

Hi, my name is John. I’ve been using and collecting fountain pens for over 20 years. I got my first one in college when I wanted something different to take notes with. I run the site FountainPenLove.com.