January 24, 2016
I bought nearly every block eraser that Japan makes in a recent shopping binge.
As a math major, I need lots of erasers as it is, but I also wanted to determine
which ones worked best for my needs. I tested all of the erasers on three
different types of pencils: a Pilot Eno color .7, a Pentel graphite .5 and a
Pentel color 2mm, and then on three different paper types: Rhodia, an index
card, and then plain old American junk copier paper.
The type of paper wound up not mattering with the performance of any of the
erasers. What mattered was what lead they were erasing.
So with that established:
The Kokuyo isn't a very sexy eraser. Other erasers have a certain wow factor,
like the Boxy and it's sleek black square that's so easy to hold, or the Seed
erasers that glow in the dark, or are made of cute colors, or come with a
sophisticated gold eraser holder.
However, the Kokuyo is a workhorse at what it does: Erasing. It was easily a top
5 eraser when it came to .5 and .7 leads, and it required very little effort to
clear heavy marks.
It doesn't work so great on the 2 mm Pentel color leads, which are supposedly 2B
in lead hardness. The Kokuyo requires a whole lot of elbow grease to get Pentel
Color marks to clear out, and, even then, it leaves some of the color behind. I
use the Pentel every single day for graphing, so I need an eraser that can
handle that. It's sort of the deal-breaker, and the Kokuyo failed there.
I'll keep it around for normal pencil tasks, because it does so well at those;
however, I won't be buying more.