Sharpening, Acute and Obtuse

I’m not sure whether you’ve seen the cover of Daniel Kahneman’s book “Thinking, Fast and Slow”. On the cover is what looks like a Mongol with an incredibly acute point.

The angle of the pencil point seems to be 14°. I assume the image has not been stretched. Ok, the pencil looks as if it has been bitten specifically for the purpose of this photo. The eraser also looks as if it has been used up for the sake of using it up, uniform use with no trace of lead – but that point….

The pencil on the book cover next to a Venezuelan-made Mongol

 

14°… and it doesn’t look knife sharpened! Currently my list of sharpeners sorted by angle doesn’t have any sharpener that comes close to this. Unfortunately the book’s colophon doesn’t mention the photo on the cover. The UK edition states that the cover is designed by Yes, but there’s a good chance they just ‘rearranged’ the American cover and don’t have much to do with the pencil on the cover.

Any hint on what sharpener has been used to sharpen that pencil would be greatly appreciated.

 

I’d like to thank Sean because I got most of my Mongol pencils, like the one pictured, either through him or because he made me aware of where to get them. Thanks!

Guest Review by Kevin of the Dahle 133 rotary sharpener (and Deli 0635 rotary sharpener)

Recently I purchased the Dahle 133 rotary sharpener from Amazon  UK. I wasn’t expecting a great sharpener given it’s bland looks in dull grey and black. There were however some features that drew my attention to this sharpener.

  1. The protected grippers that do not mark the pencil, unlike the usual metal “jaws of death” seen on most rotary sharpeners.
  2. The sharpener is advertised as having 2 point settings – sharp or blunt, however the screw type mechanism seems to allow for an infinitely variable sharpness between these two extremes.
  3. Low cost, from 7-10 pounds sterling depending on colour. I didn’t realise Amazon were also offering a green and white and black and white model for a couple of pounds less than my model.
  4. Sharpens pencils from the usual standard around 7mm up to 11.5mm for some chunky art pencils.

PERFORMANCE

As my main interest is graphite pencils, I sharpened a selection to see if it produced a point comparable to my gold standard sharpener – a modified (with padded grippers from the premium model) Carl Angel 5 (chinese mechanism). Here’s the results.

  • Standard diameter hex pencils such as the Faber Castell 9000 and Tombow Mono 100 produced a short exposed core and a dull point. Not impressed.
  • The round barrel Papermate Black Warrior (Mexico) produced a nice long cone and good point sharpness.
  • The oversize triangular Dixon TRI-CONDEROGA sharpened nicely with a long cone and medium/long exposed core.

While not as good as a Carl Angel-5 it does have the advantage of padded grippers and the ability to sharpen oversize pencils. I would give it a 6 1/2 out of ten for graphite pencils. BUT, and here’s the big BUT, this sharpener is absolutely brilliant with all the coloured pencils I tested. It seems the thicker cores of coloured pencils – 3mm and up are better suited to the geometry of the mechanism than thinner cored graphite pencils.

- the overall cone (wood and core is long and nicely tapered) and the exposed core is almost razor sharp and with just the right length.

For comparison I sharpened a graphite pencil and more coloured pencils in one of Matthias’ favourite sharpeners – the Deli 0635. The result for the graphite Berol Turquoise was quite good but the point and cone shape/length not up to the standard of the Carl Angel 5. But, yet again the coloured pencils were sharpened to an almost absurdly l.o.o.o.ng cone length and the exposed core is also massively long and deadly sharp, even sharper if that’s possible, than the Dahle 133.

Of the two sharpeners I would plump for the Dahle 133 for the more reasonable length of the cone and the exposed core. The Deli 0635 cone is simply freakishly long and sharp and thus the point strength is compromised.

OTHER POINTS OF INTEREST

Both these sharpeners would fit easily in most outdoor art sketching kits. The Deli 0635 is super compact and the Dahle is compact – about half way between the Carl and the Deli in size.

Both these little sharpeners are basically plastic externally but have robust all metal cutting cylinders with all metal gear drive.

The padded grippers on both sharpeners was the main reason I purchased them and in this regard they do their job admirably. I only wish that manufacturers and sellers would promote these padded gripper models as a feature – which they certainly are.

Given the results with coloured pencils, I will certainly be using mine more often in future.

Thanks to Matthias for the airing of this guest review.

 

You can find another review of the Dahle 133 at Lexikaliker (Google translation of the blog post).

MAD

Was Mad Magazine a staple in your diet of comics and magazines when you were younger? If so you’ll probably like these:

A Spy vs. Spy Pencil sharpener gag by Bob Clarke.

 

Spy vs. Spy (Image © Bob Clarke)

…and another pencil sharpener gag from the The Mad Student Survival Guide for Those Bored of Education.

(Image © Mad Magazine)

 

I’d like to thank Anthony Snyder for allowing me to show Bob Clarke’s drawing. He is currently selling this drawing on eBay.

The image of Bob Clarke’s Spy vs. Spy comic is from Anthony Snyder, who allowed me to show it in my blog. The sharpener gag is taken from The Mad Student Survival Guide for Those Bored of Education. I believe that the use of these images in this blog post falls under “fair dealing” as described by the UK Copyright service.

Magnesium sharpeners

Unfortunately I don’t know too much about chemistry. Even though the Bavarian school system provided me with 13 years of education1, the type of school I went to and the modules I picked meant that I only ever had one semester of chemistry – so please forgive me and correct me if I am using the wrong words in this blog post.

A few days ago I noticed that my magnesium sharpeners look pretty bad. The surface is now very rough, not shiny any more at all, except for some small areas. The sharpeners have been stored together with a silver plated letter opener I bought very cheap from The Pen Shop. A few erasers were also next to the sharpeners for a long period of time. I’m now wondering what caused the corrosion/tarnishing of the magnesium.

Maybe someone who knows more about chemistry can tell me what happened – so that I can avoid similar mistakes in the future.

Click to get a better look how the surface looks like now

 

My first idea what might have happened: A process similar to the one when aluminium is used to clean tarnished silver took place. The magnesium sharpeners kept the silver-plated letter opener untarnished, because magnesium is less noble than silver and therefore attracted sulphur or other chemical elements.

My alternative suggestion: Just like the chemicals from another eraser ‘ruined’ one of my wooden pencil boxes once, the chemicals from the erasers that were stored together with the magnesium sharpener changed the sharpeners’ surface, too.

Can anyone tell me what really happened to the magnesium sharpeners?

  1. I think this has now been reduced to 12 years. [↩]

A trip to the museum …and a new sharpener

Thank you for the anniversary comments. I was hoping to get this blog post out by 21 November, the third birthday of this blog, but unfortunately I didn’t find the time. Anyway here’s the first blog post in the fourth year of Bleistift.

The Cumberland Pencil Museum

 

The museum

Considering that I don’t live too far away from the Cumberland Pencil Museum, both the Museum and I are in North West England, it took me quite a while to get there – but this May my wife and I finally made the trip. The weather was fantastic and the Museum managed to convey a lot of information despite being rather small. Admission is £4 (~$6.40; €4.95), but comes with a ‘free’ souvenir pencil.

How pencils are made - temporary(?) mural outside the museum. Notice the "i" in weird.

There were explanations how pencils are made and you could admire historic pens and pencil and machines. I will only show one photo from inside the museum as I haven’t asked whether they permit the posting of photos taken in the museum on the web.

On exhibition: Cumberland pencils from the 1920s

There was a pencil labelling machine, too, but unfortunately it was broken at the time …I would have really liked to get some personalised pencils.  A subsequent enquiry regarding the pencil labelling machine was not as helpful as it could have been, so I decided not to chase this up further. Maybe the machine will work again if I go there again in the future.

The Pencil Museum Shop

Obviously I couldn’t resist stocking up on pencils in the museum shop. The shop’s selection is aimed at artists, but if you use pencils for office purposes you’ll also find nice products. Pencils are from Derwent, who are running the museum, but you can find pencil related items from other brands.

The Eisen 060 sharpener, top

 

The sharpener

One of the products I picked up in the museum is the Eisen 0601. I like this sharpener because the rounded corners make it “different” while still maintaining the classic wedge shape look2. I paid £1 (~$1.60; €1.25). This sharpener’s body and blade were both made in Baiersdorf near Nuremberg. The 060′s produced in the last three years still feature the blade made in Baiersdorf, like all Eisen sharpeners, but the body is now made in Taicang near Shanghai. Performance of this little sharpener is very good, too.

The Eisen 060 sharpener, bottom

Technical Information (adapted from Pencil Revolution)
Type wedge / blade
Material Magnesium-alloy
Shavings Receptacle None
Angle 24° – 25°3
Markings “MADE IN GERMANY” (blade); Eisen logo plus “Made in Germany” (body)
Place of Manufacture Baiersdorf (Germany) and Taicang (China)

The Eisen 060, a Wopex and the Museum pencil

 

Giveaway

As this is a (belated) birthday blog post I am giving away an Eisen 060, some British-made Staedtler pencils and possible a few other small items I can find. I am happy to send the prizes to any country as long as Royal Mail doesn’t refuse to send them there. I will use random.org to get a random number and the author of the corresponding comment will get the price (unless I am the author or the comment is definitely spam). To take part please leave a comment for this blog post before Friday, 30th September 2011, 23:59 UTC.

 

Prices: May 2012

Exchange rates: November 2012

I would like to thank Stephan Eisen for providing additional information regarding the Eisen 060.

  1. Eisen changed their web site. The pages are only available in German at the moment, so unfortunately all links to Eisen are to their German product page. [↩]
  2. Eisen’s classic wedge sharpener is the 040. [↩]
  3. I measured 25°, the official figure is 24° which is also the one I used for in the list of sharpeners [↩]

Sharpening a Wopex …again

My previous experience with KUM sharpeners wasn’t very good. Some of the models I have are good, some are not so good and overall I usually prefer sharpeners from other brands.

You might remember that the Staedtler Wopex is a difficult pencil to sharpen. Nevertheless, I like it so much that on an average day it is my most used pencil. Even though sharpening it with a knife yields good results I thought I should try sharpening the Wopex in KUM’s Automatic Long Point 2M, a sharpener I haven’t used in a while because of the unsightly marks it leaves at the base of the exposed graphite1. To my surprise I got fantastic results when I used it to sharpen a Wopex.

KUM’s Automatic Long Point 2M and Staedtler's Wopex

I get best results if I align the Wopex with the top of the sharpener during the second step. If you have a Wopex and the Automatic Long Point 2M try them out. My Long Point sharpener performs much better than the dedicated Wopex sharpeners I have.

Pencil talk has a review of KUM’s Automatic Long Point 2M.

  1. These marks are one of the reason why I prefer the Deli 0635 or the Eisen 402. [↩]