Pentel – pencil talk | pencil reviews and discussion

May 7, 2017

A custom Pentel Kerry pencil and a surprise from Clairefontaine

2.0mm Pentel Kerry

Sometimes familiar stationery items aren’t what they seem. Here is a Pentel Kerry mechanical pencil – but unlike any most of us have ever seen. It is paired with a Clairefontaine pocket notebook.

2.0mm Pentel Kerry

This pencil – a classic – is a custom modification by isu of the uncomfortable chair, turning the pencil into a 2.0mm version! It continues to fully function as a mechanical pencil. Look at the quality of the finish – it appears as if it came from the factory.

Thank you isu for such a wonderful gift!

2.0mm Pentel Kerry

As to the the second surprise – let me mention some context. Many of us were very surprised to learn that Tombow has moved (at least some) production of their iconic Mono 100, one of the world’s best pencils, to Vietnam. There is a great account at Lexikaliker. The news so far isn’t good – unfortunately, the Vietnamese version appears diminished in finish quality, even if retaining the same lead core.

So what a surprise to find a notebook the same week from Clairefontaine, which like sibling brands Rhodia and Exacompta, strongly associates itself with “Made in France”, that is made in Morocco. Yes, “design” and “paper” from France. Fortunately, I find the notebook to be excellent, with creamy 90 g/m² paper (presumably the same as the “Rhodia R” series) and a pocket format. I’ll note a particular pencil advantage – this thick paper takes well to traditional rubber erasers, such as the round Graf von Faber-Castell.

March 29, 2010May 23, 2021

Mark Sheet pencils from Japan

These pencils aren’t aimed at writing, yet they are all superb at the task.

Sold to students facing multiple choice exams, they are specialty test pencils. These specific ones are made in Japan, and called “Mark Sheet” pencils.

Of course, test taking isn’t the only possible use, and today we’ll take a look at them from a writing perspective.

Mark Sheet pencils from Japan

The pencils are:

Mitsubishi Uni 100 Mark Sheet pencil, HB
Pentel CBM10 Mark Sheet pencil, HB and B
Tombow LM-KMS Mono Mark Sheet pencil, HB

All are hexagonal with finished caps, and sold unsharpened.

Mark Sheet pencils from Japan

The Mitsubishi is grey, with a black dipped end and blue ring. The lettering is white, and the pencil states, “Hi-Density Lead for Mark Sheet.” The cap is stamped “HB”.

The Pentel is navy blue, and has the slogan, “the best quality for OCR sheet marking.” The blue is offset by two silver rings and silver lettering. The HB has a marigold cap, while the B grade sports red.

The Pentel has a vivid bright blue finish, with a matte silver dipped end and silver ring. The lettering is in white.

Mark Sheet pencils from Japan

All three pencils have nice finishes, and sharpen easily.

Certain pencil/paper combinations really shine (a subject for a future post), and on a Maruman Mnemosyne notebook, all three pencil brands are exceptional in their non-crumbling adherence, smooth application, and dark rich black lines. The best? For me, the Pentel, and especially the B grade version, stood out as a super-smooth writer.

Mark Sheet pencils from Japan

Specialty pencils of course have specialty erasers, and the Uni Mark Sheet eraser does a great job. The formula seems somewhat different than other familiar erasers from Pilot or Tombow – more crumbly, but possibly even more effective.

Mark Sheet pencils from Japan

(Pentel also make a “mark sheet eraser”, but I haven’t seen it in person.)

All are first rate, but writing with the Pentel CBM10 Mark Sheet pencil in B is an experience I especially recommend to all pencil users!

Pentel woodcase pencils

Though Pentel may be known for mechanical pencils and lead refills, their woodcase pencil products are equally outstanding.

In our lineup today, we have:

Pentel Mark Sheet Pencil

Pentel Tuff Pencil

Pentel Black Polymer 999 Copyist

Pentel Black Polymer 999

Pentel Black Polymer 999? (999 alpha)

The Pentel Mark Sheet pencil is Pentel’s entry in the test scoring category. In HB, the pencil is dark blue with silver lettering. The cap is dark yellow/light orange. As a pencil, it is astounding. It sharpens easily, and writes incredibly smoothly, leaving an extremely deep, rich, saturated line – that is also erasable.

Pentel woodcase pencils

The pencil was not an entrant in last year’s test of the top Japanese pencils, but it might have been a contender. It is just amazing!

The TUFF pencil is a mystery to me. In grade H, it writes very nicely. I think it would be extremely satisfactory for someone seeking a pencil that keeps a sharp point, and writes smoothly, with a line as dark as most mainstream HB pencils.

Pentel woodcase pencils

Next, we have a turquoise version of the Pentel Black Polymer 999. The pencil has a turquoise finish and Japanese language text. Automatic translations of Pentel literature call this a “pencil for copyist” or “copyist pencil”. Perhaps someone can advise?

The space for a name on the side of the pencil suggests it is for students.

What I do know is – it is a fantastic pencil! The smooth writing qualities just amazed me. It’s nice on cream paper, but on a white paper like Clairefontaine or Rhodia, the dark rich graphite just pops! My only reservation is the turquoise colouring, which I am not sure I like.

Pentel woodcase pencils

The “regular” Pentel Black Polymer 999 in HB is another well known top pencil. My growing impression is that it trades just a bit of smoothness for deep blackness, without the production of crumbles. The 4B in the series is quite amazing, creating super saturated black lines. What’s in the pencil? Is it a “polymer lead”? Stay tuned … I think we’ll learn more in the future.

Pentel woodcase pencils

The Pentel Black Polymer 999? is the top of the line. In H, it would be fine on bright white apper. I think it is quite a bit smoother than the TUFF, the other H grade pencil. It also boasts an extremely nice black lacquered finish. Though there is too much text for my taste, it is a very classy looking pencil.

Pentel woodcase pencils

We’ve heard that Pentel isn’t a woodcase pencil manufacturer per se – they subcontract their production. What can we say? Well done! The only possible criticism I can think of is that they don’t have as full a range of grades as their competitors. But everything they have done is first-rate.

Pentel woodcase pencils

The online Pentel 2009 catalogue shows the Pentel Black Polymer 999, Pentel Black Polymer 999 Copyist, and Pentel Mark Sheet Pencils. The others may be discontinued.

Name	Slogan	Model	Bar Code	JIS symbol
Mark Sheet	the best quality for OCR sheet marking	CBM10	yes	no
TUFF	HI-QUALITY	CB6	yes	yes
Black Polymer 999	*	CB1	no	no
Black Polymer 999	the highest quality for general use	CB100	yes	no
Black Polymer 999?	supreme quality for drawing lines of high density	CB200	no	yes

Pentel woodcase pencils

Nice pencils, Pentel!

The pencils were shown on a Mateo Ilasco No. 309 “Blueprint” notepad, and sharpened with a Carl Decade DE-100 sharpener.

My thanks to isu from the uncomfortable chair for kindly sending me the majority of these pencils.

March 3, 2009May 14, 2010

The curious arithmetic of mechanical pencil refills

Pentel Ain lead refills

Hmm, has anyone noticed this aspect of mechanical pencil refills?

Pentel Ain refills (just to pick a particular brand) are all the same price.

And all are 60mm in length.

But they contain:

0.3mm – 20 pieces
0.4mm – 30 pieces
0.5mm – 40 pieces
0.7mm – 40 pieces
0.9mm – 36 pieces

What gives? Thinner lead costs more? I would think one would get more pieces of thin lead per dollar.

If you calculate volume = length * pi * radius * radius

Then single pieces of lead are:

0.3mm = 60mm * 3.14 * 0.15mm * 0.15mm = 4.24mm³
0.4mm = 60mm * 3.14 * 0.20mm * 0.20mm = 7.54mm³
0.5mm = 60mm * 3.14 * 0.25mm * 0.25mm = 11.78mm³
0.7mm = 60mm * 3.14 * 0.35mm * 0.35mm = 23.08mm³
0.9mm = 60mm * 3.14 * 0.45mm* 0.45mm = 38.16mm³

That’s right – a 0.9mm lead is 9 times the volume of a 0.3mm lead! (Which makes sense as the volume is proportional to the square of the three-times-larger radius.)

So as to how much lead is in a Pentel Ain box:

0.3mm: 20 * 4.24mm³ = 84.80mm³
0.4mm: 30 * 7.54mm³ = 226.20mm³
0.5mm: 40 * 11.78mm³ = 471.20mm³
0.7mm: 40 * 23.08mm³ = 923.20mm³
0.9mm: 36 * 38.16mm³ = 1373.76mm³

That’s right – for the same price, a 0.9mm user gets 16 times more lead in a box than a 0.3mm user!

Curious?

September 8, 2008

Very thin erasers

Here are a couple of amazingly thin erasers.

The Tombow Mono zero is a 2.3mm diameter cyclindrical eraser, dispensed by clicking the cap. It really does seem like a mechanical pencil in both form and function.

I thought this eraser was probably a borderline novelty, but it worked quite well over a period of days. You wouldn’t use it to erase several lines of text, but it is great for smaller tasks such as changing a line fragment, digit or letter.

I like the portability as well.

Very thin erasers

The Pentel Clic Eraser Hyperaser is a rectangular metal housed eraser. It has a dispense mechanism similar to that of most stick erasers, such as the Staedtler 528 50. A clip as well!

This is an ink eraser. It seemed to work well on tests with ballpoint ink, and less well with fountain pen ink.

I wasn’t expecting much, but both seemed pretty good.

The main problem I see it that both require yet more proprietary refill types. The Mono zero in particular seems like it will require a replacement eraser soon enough.

Very thin erasers

My thanks to der Lexikaliker for the Pentel eraser.

August 26, 2008May 15, 2010

Pentel Mark Sheet Pencil

We’ve seen special pencils aimed at optical and electro-mechanical mark recognition – the vintage IBM Electrographic, and the more recent Musgrave Test Scoring Pencil.

Quite a few people seem to be interested in these pencils, so I’m pleased to be able to mention a superb modern example that I recently learned about – the Pentel Mark Sheet pencil.

This hexagonal pencil is finished in blue with silver lettering. Two grades exist – HB, which has an orange cap, and B, with a red cap.

The pencils are marked –

Side 1: Pentel Mark Sheet Pencil HB

Side 3: the best quality for OCR sheet marking CM10 Japan HB

Side 5: [bar code]

Pentel Mark Sheet Pencil

The lead is just superb – at the pinnacle of modern graphite quality. The pencils leave extremely dark, rich lines. There is often a crumbling issue when a pencil’s graphite saturation reaches this level, but these pencils have no such problem.

It would be hard to imagine a better performing pencil.