Fountain pen ink must be water based, in order for the capilliary action in the pen to work. Unfortunately, this means most fountain pen inks are inherently washable – if your notes get soaked in the rain or run through the washing machine, you’ll get back a mess. While I’m not convinced anyone will read anything I’ve written after I’m gone, I can’t stand losing information to accidents.

Ballpoint inks and some rollerballs (like the Uni-balls with “Super Ink”) are generally pretty water resistant. They seem much less enjoyable to write with, and certainly don’t come with the “fiddleability” that appeals to one’s inner geek.

For a long-time, I’ve been trying to use water-resistant inks in fountain pens to try to get the best of both worlds. The two Montblanc pens I’ve favoured at work, are usually loaded with Montblanc blue-black (now “Midnight Blue”), which is an iron gall ink, and is therefore pretty water resistant.

Other pens have mostly been inked with Noodler’s Black. This ink claims to be “bulletproof”, resisting any attempt at removal that doesn’t destroy the paper as well. I also really like the colour of this ink; it’s a very bold black in the right nib.

Neither black or blue-black is really good for annotating and editing documents; it’s too easy to miss an editing mark in a page of text. Consequently, there’s often another pen inked (with a fine or EF nib) with a brighter colour: Noodler’s Purple Martin, Navy, and Forest Green; Montblanc Lavender Purple, Oyster Grey, and Racing Green. I wondered about the water-fastness of these inks, even though they aren’t advertised as being waterproof.

So, a test was in order. Rather than just testing water resistance, we pushed a little harder: the test pages were soaked in scalding hot water with laundry detergent for ten minutes, then rinsed in cold and left to dry. There were two test pages: one full of all sorts of ink, and one with three permanent inks.

Colour inks

I tested the nine inks in my study (others are in boxes elsewhere), which are the most often used. You can see a scan of them before washing below:

and after washing:

As you can see, most of the colours were significantly degraded. The Forest Green, Purple Martin and Quick blue-black were nearly entirely washed away. Most of the Montblancs were still readable but very noticeably faded. The Montblanc blue-black, in particular, fared much worse than I expected. Noodler’s Navy mostly stayed, and the bulletproof black wasn’t noticeably changed at all.

The destruction of the paper probably pays testament to quite how harsh this test was.

Permanent inks

The second test pitted three inks head to head, with a a ballpoint control: the Montblanc permanent blue-black, Noodler’s bulletproof black, Noodler’s partially water resistant Navy, and a Uni-ball Power Tank.

Before washing:

In the sink:

After washing:

I was stunned at how effectively the Montblanc blue-black was washed away! Barely a trace was left.

The smudges on the Noodler’s black happened when I was patting the paper down on the drying surface. My fingers smeared the ink a little, but the original is still clearly visible.

Noodler’s Navy put in a good performance, but was quite variable. The different colour in the middle of the page was where the granulated laundry powder landed on the page. All in all, though, it survived pretty well for an ink which only claims partial water resistance.

Thoughts

Noodler’s black is what it says on the label, within my ability to test it. The other inks, though, are just as soluble as you might expect; don’t rely on them to resist water (or the washing machine).

As my wife pointed out, at least we now know how to get Montblanc blue-black out of clothing if it leaks!