What is the best waterproof fountain pen ink? I would have to answer this by saying it depends on what you are planning on using it for, the type of paper you are using and on your own personal preferences. Also, depending on your expectations, you may feel that there are no fountain pen inks that are truly waterproof. Let me explain.
While there are different forms of waterproof ink on the market, not all inks are suitable for use in a fountain pen. Some types of ink can harm or clog your fountain pen, so unless the ink is specifically formulated for fountain pens we cannot recommend using it. Fountain pen ink is water based, and therefore water soluble, and is either dye or pigment ink.

Noodler’s Ink has created many colors and types of dye based ink that are what they call “bulletproof.” Here is how Noodler’s currently defines “bulletproof”:
“Bulletproof” refers to any Noodler’s Ink that resists all the known tools of a forger, UV light, UV light wands, bleaches, alcohols, solvents, petrochemicals, oven cleaners, carpet cleaners, carpet stain lifters, and of course…they are also waterproof once permitted to dry upon cellulose paper. Some inks are more bulletproof than others – generally in descending order (most bulletproof with the most testing – to less bulletproof): blacks, blues, yellows, invisible (“blue ghost” and “White Whale”), greens, browns, purples, reds….all are equally bulletproof with one exception: the resistance to strong industrial bleaches to the point where the paper structure itself decomposes. Reds are prone to more fading when exposed to strong bleaches (sometimes fading to a yellow) than the other colors.
Noodler’s has also gone a step further and created the Warden’s series of inks which in addition to being “bulletproof” also resist several new technologies that could potentially be used by forgers.
In what way are these “bulletproof” inks waterproof? When the ink has a chance to react with the cellulose in paper, it forms a bond with the cellulose and cannot be washed out of the paper. “Bulletproof” ink that does not bond with cellulose CAN be washed off.
Noodler’s bulletproof inks are a good choice if you want to address an envelope and make sure the address doesn’t get washed off by the rain. They are also good for writing checks or for writing other documents where resisting crime/fraud is important. If you want to make sure your precious notes or journal do not get obliterated due to a coffee spill, bulletproof ink is also a good choice. Some of the ink may run or wash off of the page or even fade in color when exposed to water, but the ink that has bonded with the cellulose will remain. You can expect differing results with this ink depending on what type of paper and pen you use.

If you want to use black fountain pen ink along with watercolor paints for artwork, your best choice would be a water-resistant black pigment ink meant for fountain pens such as Platinum Carbon Black. This ink contains ultra-fine pigment powder that makes the ink very water-resistant, fade-resistant and heat-resistant after it dries. It is possible that this ink could clog a fountain pen, so careful fountain pen maintenance is required when using this ink. Depending on the situation, a small of this ink may wash off with water, so it is not perfectly waterproof. Again, you can expect differing results depending on what type of paper and pen you use. Platinum pigment inks are also available in red, brown and blue colors.
Of course there are other types of water-resistant fountain pen ink available, with varying degrees of resistance to water. We’d love to hear which one is your favorite, why you like it and what you like to use it for!





