How to sharpen pencils


Pencils – unsharpened and hyper acute

When looking at pencil points there are all sorts of angles you could sharpen a pencil to.

I guess an angle of 180°, i.e. an unsharpened pencil is as low as you could go – unless you want an angle > 180°.

Here’s a photo of an unsharpened pencil, seen in Season 10 of Inspector Montalbano (Il commissario Montalbano), between the two eraser-tipped Noris pencils. You can see his other pencils in this blog post from 2012. Where they got an unsharpened Noris from is a mystery to me. Maybe they removed the pencil point of a factory sharpened pencil?

Episode: A Delicate Matter (Image © RAI)

On the other hand you have pencil like the ones from Pencil Guide that seem to have an angle of 6.8°1 (for comparison: the KUM Masterpiece has an angle of 15°). They look deadly.

Gunther explains:

If you create a point with an angle of 6.8° (cone angle 3.4°) on a pencil with a diameter of 8 mm you expose the wood at a length of approximately 67.6 mm. This length and the pencil’s length are in a ratio of approx. 1:1.618.

1:1.618 is the golden ration.

Pencil Guide calls itself a pencil sharpening service company, but they only sell sharpened pencils and don’t follow David Rees’ business model.

(Image © Pencilguide.com)


I would like to thank Jun-Haeng Lee for the information about Pencil Guide.

The images in this blog post have been taken from Pencil Guide and from episode A Delicate Matter of the RAI TV series Il commissario Montalbano. I believe that the use of the images shown in this blog post falls under “fair dealing” as described by the UK Copyright service.

  1. Thanks to Sola and Gunther I now think the angle might be 6.8°. []

Sharpening a Wopex 11

You might have already noticed that the Wopex is one of my favourite pencils. It is the pencil I use most often when writing on paper where ghosting/graphite transfer might be a problem. There is however one problem that makes using a Wopex an experience less exciting than it could be: sharpening this pencil.

Wopex, presharpened

Desktop sharpeners are not good at sharpening pencils with such a hard casing. They won’t stop automatically, too, which means that you might shorten the pencil too much when using a desktop sharpener and you’ll got a less than exciting finish where the blade cylinder stopped.

Wopex, prism sharpener sharpened

Click to enlarge

A normal prism sharpener does a better job when it comes to sharpening a Wopex, but the lead tends to look rather porous after sharpening and the fine point created will break much easier on a Wopex than on a pencil with a traditional lead.The special Wopex sharpeners don’t seem to do a better job than any other prism sharpeners. At least they don’t do for me, maybe I don’t use them the way they should be used. One example is shown here, but the point doesn’t always look that bad. A better looking point, made using a prism sharpener, has been shown in a previous blog post.

Wopex, knife sharpened

The presharpened Wopexes1 are looking and performing best. They are sharpened on an abrasive surface, something that is not necessarily practical for home use because of the time and dust involved. Searching for an alternative, better than a normal prism sharpener, I thought of using a knife to achieve a point similar to the one of presharpened Wopexes.

Unlike most other sharpening techniques, in which blades engage the pencil’s wood (and later, graphite) at an angle more or less parallel to the shaft, the pocketknife’s blade is applied perpendicular to the pencil’s shaft.” (Rees 2012, p.46)2

There is a special pencil knife for sharpening and erasing, but I used a normal knife. In this case one with a high carbon steel blade, but stainless steel blades work just as well. The results are good, better than what I get from a prism sharpener, including the Wopex sharpener, but are slightly worse when compared to a presharpened Wopex.

 


I would like to thank

  1. Wopeges, Wopeces? or whatever the plural may be []
  2. Rees, D., 2012. How to sharpen pencils. Brooklyn, New York: Melville House. []