Stationery Tips

Lead of mechanical pencils

History of Spare Leads

Since the release of the Eversharp in 1838, the Spare Leads was made of graphite clay (same as pencil core), with a core diameter of 1.0 and 1.5 mm length of about 30mm. However, in 1962, a 0.5 mm synthetic resin core was released, and the core technological innovations took place.
The Tombow was produced in the graphite clay core ” MONO -Do”, and was approved by the Spare Leads JIS Display permission factory in 1961. Then, in 1965, the synthetic resin core “PLA” was released.

Back to Stationary Tips


Digital catalog is available for online reading.

General Info Catalog

General Information of Tombow 2022-2023 Lineup of all products of Tombow

Open the catalog

Eco Info Catalog

Information and lineup of environmental products of Tombow

Open the catalog

Downloadable PDF version is available.

Catalogs can be viewed and saved in smartphone, tablet and PC in use of “iCata” digital catalog service.

Product information in catalogs is created at the time of catalog production. Please note that design, specification and other information may change without notification.