Which drawing pens are the most waterproof?

I sometimes like to sketch with a drawing pen before I paint over it in watercolor. Essentially, I’m making myself a coloring page using liners, brush pens, or both. However, I find myself often using pens which smear when I begin to paint over them. This is a great way to ruin a line drawing and muddy up a painting before I even start.

But which pens are actually waterproof enough to use with watercolor? I tried all the pens from the JetPens Waterproof Pen Sampler and the JetPens Waterproof Brush Pen Sampler to find out.

Method

For each pen, I drew a squiggly line on my Arches Hot Press paper and then, almost immediately, painted over them with slightly dirty watercolor wastewater. I did not significantly wait for them to dry any longer than the time it takes for me to wet my brush. This is probably unfair to many of these pens which may indeed be waterproof once the ink fully dries, but it was the best possible test of the conditions under which I want to use these pens in the field.

I did not have a consistent thickness of pen to try, and it’s my suspicion that some of the thinner lined pens did unusually well because they were quicker to dry, but I won’t be able to test that systematically until I buy more pens.

Results

Ohto Graphic Liner (02 size, 0.3mm) – Fail. Smeared and turned the water gray, which is a shame since I liked this one to write with. I previously had a good opinion of this pen, and I think I had used it before to draw before painting, so I do think this one is waterproof if you let it dry fully. Still, not reliable enough for me to rely on everyday.

Deleter Neopiko Line 3 (05 size, 0.5mm) – Pass. Wonderfully waterproof! And this was one of the thicker pens, too, so this is a really quick drier. A++++

Copic Multiliner (0.1mm) – Pass. Totally waterproof! This one is quite thin so I’ll need to try a thicker size. (Do not confuse with the Copic Comic Drawing Pen which is not shown here, because I already left it at work after discovering it was extremely non-waterproof and smearing a drawing badly. Supposedly there is a version with waterproof ink and one without, and I’m not sure if I was sent the wrong one or if it just takes way longer to dry than I could handle.)

Sakura Micron (005 size, 0.2mm) – Judgement call. It didn’t smear, although it looks like the water I painted over it got slightly grayish. I have painted over this one before so I know that if you give it a minute to dry, it will be waterproof. Still, if I can, I’d rather go with a pen that dries ASAP to minimize the amount of time I spend in the field worrying if my pen is dry enough yet. Even a slight cast of gray can severely affect the appearance I’m going for with the watercolor.

Sakura Pigma FB (brush) – Fail. Turned the water pretty gray. 🙁

Sakura Pigma Sensei (06 size, 0.6mm) – Fail. Lots of discoloration.

Zebra Zensations Disposable Brush Pen (brush, fine) – Qualified pass. The water is slightly gray but it might just be getting dirty from the previous attempts at this point. I have a lot of experience with this pen, and I find it to be quite reliably waterproof, although it is a thick line so you might want to give it a minute to dry before painting over it. Still, even when I painted over it right away, I got minimal discoloration and no smearing. These are medium-soft brushes, firmer than the reusable Pentel Pocket Brush Pen but softer than either Tombow, and all three sizes get an extremely nice variety of line widths.

Uni Posca Paint Marker – Fail. I don’t think this one ever said it was waterproof, so fair enough.

Staedler Pigment Liner (0.7mm) – Fail. Discoloration and smearing.

Sakura Micron Brush – Fail. Lots of gray water.

Pitt Artist Pen – Fail. To be fair to it, it advertises itself as “water resistant.”

Kuretake Disposable Pocket Brush Pen (brush, extra fine) – Pass! At this point the very slight discoloration in the water is simply because it is dirty. The pen didn’t smear at all. This is a very firm brush that straddles the line between a brush and a felt-tip pen.

Tombow Fudenosuke (Soft & Hard) – Pass! Very similar to the Kuretake. The Hard is noticeable harder than the Soft, but even the soft is quite firm, similar to the Kuretake – much firmer than Zebra.

Uni Pin Pen 01 (0.28mm) – Judgement call. Water didn’t turn gray, but I’m seeing very slight smearing along the crests of the curves, not promising in a super-thin size like this.

Not Shown: The Pentel Pocket Brush Pen, which I couldn’t get to work. The ink wouldn’t come up into the brush no matter how carefully I followed the instructions. I think I got a faulty cartridge.

What About Fountain Pens?

Typical fountain pen ink cartridges aren’t waterproof, but you can fill your fountain pen with waterproof ink if you have a pen with a refillable chamber (like the TWSBI Eco) or you use a converter. You then draw up the ink into the pen like a syringe. For awhile I was doing this method, using a fountain pen with waterproof ink, using a Lamy Safari fountain pen and De Atrementis Document Ink. This was great and I totally recommend it, but I found that, as a lifestyle, using a waterproof-ink fountain pen wasn’t a good fit my for inconsistent attention span.

The thing is, you’re not supposed to let the ink dry in the chamber – it clogs the pen. Essentially if you’re not using the pen daily, you should be emptying it out before putting it away. But, I have a tendency to use the same art supply every day for two weeks and then, without warning, abandon it and not use it for months. I never know when I’m going to be “putting something away” for a while – it’s not predictable! My use of the pen was too inconsistent and my (in)ability to plan and predict is not a good match for a high-maintenance supply like this. So, I went back to using disposable pens.

Conclusion

Best Liner

Deleter Neopiker Line 3 or Copic Multiliner both gave me insta-dry, fully waterproof ink right out of the pen!

Best Brush

Tombow Fudenosuke and Kuretake Pocket were both fully waterproof, but both felt more like felt-tip pens than a brush pens to my hand. (Still, they’re quite nice felt-tip pens.) Zebra Disposable (sometimes called Zensations) is the most brush-like of the passing pens, though it was a qualified pass. (Personally, Zebra is my favorite! You just need to give it a minute to dry.)