Eraser Review: Tombow Mono Zero

On payday, I made my typical trip to Blaine’s Art Supply in search of some new toys & review fodder. I have so many pencils backed up to review — and yet, not enough to sustain this blog at the rate that I’m burning through them. So I forced myself to resist temptation to buy the few pencils they have remaining that I haven’t already picked up, and to branch out. I opted for something different and, in my line of work, potentially useful: The Tombow Mono Zero eraser; in this case, the rectangular version.

I have a very high opinion of Tombow products; in fact, the 8900 2B is one of my all-time favorite pencils. On the flip side, I’ve yet to meet a click eraser I actually really like. But then again, this one looks really promising. How will it pan out? Let’s see…

Form and Function

The Tombow Mono Zero eraser is a sharp-looking, retractable click or pen-style eraser. Made in Japan of black plastic with a precisely-printed grey make and model emblazoned very nicely along the barrel, the Mono Zero features a reinforced tip made of metal and a pocket clip. Although I chose the black version, they also come in silver.

The refillable “pen” body has a click-to-advance mechanism similar to a mechanical pencil. With every depression of the button at the top about a millimeter or two of fresh eraser emerges. The actual eraser is very small. In the case of the rectangular model, it is 2.5mm x 5mm; there is also a circular version with a 2.3mm diameter. These dimensions suggest that this is an eraser for precision work.

Overall, the body looks very sharp and seems well constructed. It’s smaller than the typical ballpoint pen, so it fits neatly in a shirt pocket or a pencil bag.


To test the Tombow Mono Zero eraser’s performance, I made some swatches on a Rhodia grid pad of a few common pencils: the General’s Supreme #2, Blackwing Pearl, and Castell 9000. I threw in a few less-common ones (the Lyra Groove Slim and the Nataraj Bold) because, hey, I gotta do something with all of these pencils. Then I went to town on the swatches with the Mono Zero and two block erasers that I feel represent the high and low ends of the acceptable performance spectrum, respectively: the Pentel Hi-Polymer and the Paper Mate Pink Pearl.

As shown in the photo above, the Mono Zero put up a good but not awesome performance. The Hi-Polymer, as it tends to do, made the mark practically vanish, and the Pink Pearl didn’t really remove any of the marks, but at least faded them to an acceptable level. The Mono Zero fell somewhere in between, nearly removing the more erasable pencil marks as well as the Hi-Polymer, but unable to complete get rid of all of them.

Another thing you can see from the above image is the level of precision. The Pink Pearl is a little challenging to control because of the floppiness of it. As expected, the Mono Zero was much easier to handle. However, it was pretty easy to handle the Hi-Polymer, although it had a fresh corner that hadn’t been ground down yet. The obvious advantage of the Mono Zero is that it always has a fresh edge.

The next test was for messiness. We all know that different erasers leave different quantities and qualities of crap behind them. So I wrote out three simple “Erase me!” notes on the same Rhodia pad and erased one with each test eraser, using the minimum amount of time and pressure to erase the words as completely as the eraser could.

I’d say that the Mono Zero, again, gave a performance that fell somewhere on the middle of the spectrum of goodness. It produced several very fine threads and bits of rubber. It seems like the overall quantity of material waste that it creates is good, but the fact that it leaves little pieces scattered about isn’t so great.

Finally, I want to speak on the subject of precision, since that seems to be the Mono Zero’s main selling point. I went ahead and wrote two blocks of text and chose a single letter from the middle of the block. In one block, I erased that letter with the Mono Zero, and the other I erased with a Hi-Polymer pencil cap eraser. Obviously, the Mono Zero was able to easily pick off a single letter out of a word. However, I didn’t have that much difficulty doing it with the (rather worn down) pencil cap eraser, either. It was a little easier with the Mono Zero because I didn’t have as large of an object blocking my view of the page, but not massively so. This seems like a good example of the law of diminishing returns: extreme precision might not be extremely better than acceptable precision.


The Tombow Mono Zero is a pretty solid eraser, with some pros and cons. I am slightly disappointed with the erasing performance — it has the look of a premium product, but the search for a compact eraser that removes marks as effectively as the big hunk o’ Hi-Polymer continues. That said, it’s not any worse — and probably a little better — than most compact erasers. I just had high expectations going into it.

I really appreciate the form factor of the Mono Zero. The fact that it looks and feels like a good ballpoint pen really appeals to me. I don’t really like to take my big block erasers out and about with me in my pencil bag, but the Mono Zero fits in there nicely. It also looks professional enough to carry into work meetings. I’ve noticed myself choosing it more and more for use when I’m on the go.

It handles as well as it looks in terms of erasing precision, so that is definitely a selling point. However, I’m not sure this is incredibly beneficial. Sure, it erases like a scalpel, but for my everyday purposes a steak knife of an eraser works just fine. If you ever find yourself frustrated by not being able to precisely pick apart the single molecules of graphite, the Mono Zero is about as good as it’s going to get. I just find it a little overkill.

I bought mine from the art supply store for $4.49, which I feel is a reasonable price. The refills might set you back fifty cents to a buck each. This is a bit more expensive than some of the more mainstream products like the Pentel Click, but not prohibitively so, and it looks much classier. On the flip side, and while I haven’t done the precise math, it seems like the price per unit volume of actual eraser material is higher than competitors, given the small size of the eraser refills. In other words, you’re paying the same price for less.

The Tombow Mono Zero is a pretty cool looking portable click-style eraser, but it just fell a little flat for me. I’ve owned it for over a month now and even though I’ve had it kicking around my pencil bag, I really don’t find myself reaching for it very often. Yes, it is very precise. Perhaps someone doing detailed sketching would appreciate that more than I. But for general writing purposes, it’s a bit overkill — and the actual eraser just isn’t any better than a good built-in pencil nub or cap eraser. The Mono Zero gets a very solid “meh” rating from me. Grab it if you need ultra-precise erasing, or want to look classy, but otherwise you can do better and pay less.

[Update: You may also want to check out Bleistift’s review of the Mono Zero while you’re at it!]

One thought on “Eraser Review: Tombow Mono Zero

  1. Blunt Japanese Woman September 20, 2019 / 12:42 am

    This eraser is something like a must-have if you draw: you can erase away highlights into darker areas, as well as being precise enough for detailed drawings. I love it for this purpose, but like you mentioned the eraser dust is crumbly and kind of annoying to have to deal with. I actually bought a mini broom to brush the dust away. lol


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