The World’s First Self-Sharpening Pencil
The trouble with using a mechanical pencil is that the tip of the lead changes shape as you write, thickening from a fine point to a chisel edge. Words lose their crisp shape and lines get thicker, which is particularly problematic for engineers and others that need uniform lines. The Kuru Toga by Uni-ball is the first mechanical pencil to offer a solution.
The Kuru Toga is designed to rotate the pencil’s lead by about 9 degrees each time it is pressed to paper. This wears the edges off the “chisel” as they try to form and instead rounds the lead into a cone shape, always presenting a sharpened writing point.
The way it works is that the .5mm lead is held by a toothed two-piece clutch. When the lead is pressed against the paper, the top portion of the clutch disengages from the lower piece and is pushed up. When the lead is lifted from the paper, the clutch twists and re-engages the lower piece. As the clutch twists, the lead rotates.
You can see a brief cartoon of how the pencil works at the Uni/Mitsubishi Pencil website. It’s in Japanese, but you’ll still get the idea.
Reviewers have been uniformly positive about the Kuru Toga since it’s release last year. OfficeSupplyGeek wrote that the pencil produced “the finest line I’ve ever experienced when writing with a pencil.”
The always-brilliant Dave’s Mechanical Pencils blog shows some examples of writing done with the Kuru Toga that illustrate just how well it keeps its fine point, in most cases.
One problem with the pencil seems to be the need to press down firmly and frequently lift the pencil off the paper when writing. For some users with a light touch who tend to write in uninterrupted lines, the lead may not rotate frequently enough, still resulting in chisel tips.
Still, the Kuru Toga is an improvement over traditional mechanical pencils, and it would be worth your while to give it a try. You may find that it’s the best £5 you ever spent on a pencil.