Review: Kuretake ZIG Cartoonist white ink brush pen
Kuretake’s ZIG Cartoonist white ink brush pen is a rarity in the white ink pen category.
It’s a bristle-tip brush pen while most other options are rollerballs or felt-tips that write at a fixed width.

The pen construction is very similar to Pentel’s various standard brush pens where the whole pen body is an ink reservoir. Gently squeezing the reservoir sends ink flowing into the feed and brush.
I’ve said before that ink flow in this style of pen tends to be inconsistent and hard to control, and that’s absolutely the case with the Kuretake ZIG Cartoonist white ink brush pen.

Directly after a fresh squeeze, both ink flow and opacity are pretty intense. You can tell that in above, “PEN” was written after a fresh squeeze. The thick parts of the “P” are as opaque as the ink gets, but it’s already noticeably thinner by the “N” and gradually settles into its average opacity as I wrote “SMALL.”
Ink flow is also fast and wet initially — the high volume of ink that comes out is why the initial strokes are so opaque — but this can lead to pooling of excess ink around the base of the brush, which is a great way to get ink all over your fingers and accidentally on the page.
Also, as more air gets into your reservoir, squeezing causes air bubbles, which can send white ink spraying out of the brush unexpectedly. It’s messy.

The brush on the ZIG Cartoonist is about 8 mm long and 1.5 mm at the base, shorter than most black/standard ink brush pens. Shorter brushes are easier to control, but they also have less room to hold excess ink, which is definitely a problem with white ink, which is a higher viscosity by nature.
Ink pooling and drying around the base of the brush is something you need to be constantly aware of, lest you accidentally brush ink onto the page where you don’t want it.

You can use a scrap piece of paper to wipe off excess ink and to test and temper opacity and flow, but this can be annoying if you want the ink to be thick and opaque, but, you know, consistently.
It’s really hard to get ink to be wet, opaque, and easy to control though. This is the case when you’re dipping a regular brush into a bottle of ink, too. The best solution is to go over areas multiple times to build up the opacity, or to accept some degree of blobby messiness.

The ink opacity across this fox thing is mostly that middling, average consistency. The ear fluff is way too opaque compared to the rest of it, but I went over the eye and nose a few times to try and match that max-intensity white.
On the bright side, the brush performs well with both fine and thick strokes, as long as they’re fairly short. You can get very nice, tiny marks (like in the fox’s face) and thicker, brushier bits (like in the floating fire), but ink flow will peter out quickly if you go for too long. It’s easy enough to blend multiple large strokes together (or to accept gradually decreasing opacity), but for thinner strokes, that’s harder.
It’s a good brush — the challenge is just getting the ink flow where you want it before you touch the page.

Kuretake’s ZIG Cartoonist line is obviously geared towards comic artists, and the packaging for this white ink brush pen suggests it’s to be used for highlights and touch-ups, rather than as a primary drawing tool.
I don’t think additive methods for white are better than the subtractive method, but I suppose it’s personal preference.

It’s just so much simpler to use the white of the page (subtractive) for highlights than adding the white on top (additive) after the fact, especially if adding white with a brush pen. If you must add white afterwards, it’s better to use a more predictable tool, like a white gel pen.
For character art in particular, precision really matters. Coloring in the lines of spiky anime hair with a blobby white brush pen is hard.
I redid the lineart in a lot of areas of the above drawing after adding white ink, including the turtleneck, the shoulder, and the character’s right arm.
Still, if precision isn’t as important, the ZIG Cartoonist can be pretty fun. There are definitely drawings where subtractive white isn’t practical, like for this fellow:

The ZIG Cartoonist is decent as a corrective tool, depending on the type of mistake. The white ink goes over other inks and paints well, as long as the surface is dry.
Inking black lines over the white ink is no problem, but color doesn’t hold as well, nor will it match what the color looks like on a clean page, since the white ink really can’t get back to the true white of the page and can’t absorb other inks the same way paper can.

The ZIG Cartoonist’s white ink is pigment-based and reportedly water-resistant. I didn’t have any issues going over the white ink with (wet) black once the white ink was dry.
For the below, I colored over an initial “N” with black ink (Pentel’s standard brush pen default ink, which is dye-based and water-soluable) in order to enlarge and scoot it over a bit (kerning when handlettering is hard). I did do some color and level-balancing on this photo, but you can’t really tell there was another ghost “N” under there in real life either.

White ink is finicky and difficult no matter what you do. I don’t think it’s possible for a bristle-tip brush (whether a pen or a real brush!) with white ink to have a truly consistent ink flow or opacity. So of course there are drawbacks, but this pen is about as good as I could hope for it to be.
At $9.00 MSRP, it’s priced exactly right. It’s a good quality brush with good quality ink. The reservoir refill inks are $3-5, which is, unsurprisingly, a bit higher than a typical black ink refill of the same type.
There’s an “ultra fine” version of this brush pen, which is non-refillable and more expensive, but it’s almost certainly worse. All the ink pooling and flow problems will be amplified for little gain. If you need ultra fine, get a white gel pen!

For highlights, I’ll always prefer subtractive white first, followed by precision white ink options like a Sakura Gelly Roll or Uni-ball Signo Broad, especially for character art. The ZIG Cartoonist is definitely more fun for messier stuff like monster art though, or stuff inked in a dry-brushier style.
For minor corrections, the ZIG Cartoonist can be helpful for covering slightly larger areas. It’s easier to build up opacity than the fine-line options and is easier to ink over once dry.

As a drawing or writing tool, I think you just need to make peace with its inconsistencies. (Lettering is really hard with this pen, honestly.)
Either err on the side of caution and lower opacity and just build up, or go wild with blobby, high opacity white followed by brushier, lower opacity a few strokes later. Smear white ink all over the page because you got it all over your hand. Whatever!

It always seems like finding a good white option is so tricky! I really like your uses of the white in your illustrations here though! ^^
Generally for B&W touchups, white gel pen is really convenient. But over Copic, or when I want an ultra-fine line is where it gets tricky. I have no idea why, but gel pens have never been nice over copics for me. I find it makes the gel pen ink do some funky stuff. Copic Opaque white is fine, but I don’t always love it- it’s a touch pricey for me and IIRC you can’t write over it very well.
Usually I just use white gouache. Either diluted and applied to a dip pen if I want ultra-fine lines (usually I’ll use a maru pen) or applied with a brush. There are drawbacks there too , but I’ve found it pretty nice, and more consistent than most white gel pens. (I hate when they skip ughughugh)
Have you ever done a review for Uni Posca pens? I’m curious what you think of their white options :)
Thank you! The extra thin gel pens have always been kind hard to use for me too; I think it’s some combination of the small feed, thick ink, and the smooth page surface not having enough texture to hold the ink. Thicker gel pens like the Signo Broad work a little better, imo, but I do sometimes end up using white gouache as well.
White ink with a dip nib may be the best fine-line option tbh, but yeah, you need a lot of confidence/control/experience to get consistent lines and not accidentally splatter ink everywhere (this is my number one issue with inking with dip nibs lol… I hate not being able to push on the nib and being able to only use it one directionally.)
I haven’t reviewed POSCA and kinda figured it was one of those tools where it’s been reviewed to death already maybe, lol, but maybe I’ll get around to it! I have limited experience with them but have been meaning to pick up some different size pens to have a better overview, but the small PC-1M (0.7mm) ones have good control once you get them going (they’re also finicky at start-up) but the white ink seems a bit more liquidy than than the other colors and more prone to blobbing/smearing — at least with my sample size of one.