First sold in 1967, Tombow MONO 100 pencils were manufactured to mark the occasion of Tombow Pencil's 55th anniversary.

Today, the MONO 100 remains one of Tombow's most important product offerings and is one of the most highly regarded writing pencils in the world. The MONO 100 is an artist-grade tool that demonstrates Tombow's century-long tradition of design and engineering.
 
The MONO 100 features a graphite core, and the product's name is derived from its particle density: 10 billion particles per cubic meter (100 x 100 million, as cited by Tombow's original advertising). Writing with the MONO 100 will yield velvety-smooth and distinctively dark results, and a writing/drawing experience that is leaps and bounds ahead of more cheaply produced pencils.
 
Tombow's MONO 100 is also undeniably stylish, featuring a distinctive midcentury design that was originally created by Takashi Kono––who art-directed for the 1964 Olympics and for Japan's pavilion at the 1970 World's Fair.
 
Each set of twelve MONO 100 comes in a beautiful (and reusable!) plastic window case.