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  • Writer's pictureKOH-I-NOOR HARDTMUTH

Production of KOH-I-NOOR HARDTMUTH pencil lead

At the very beginning of the KOH-I-NOOR HARDTMUTH pencil existence, there was one room - the laboratory. Imagine lots of diverse mixtures in glass bottles and a few men (in our case) who know the right recipe, i.e., the formula for the 1500 pencil in all its grades, the one for Polycolor colored pencils and many others. But don't ask them about those, for they won't tell.

Raw graphite is beautifully soft and shiny. In our laboratory, all materials are kept safe in thick wall glass jars.


Behind the discovery of graphite was foul weather? A gale uprooted a tree in English Cumberland in the 16th century, under whose roots a hitherto unknown stone appeared, so soft it was possible to write with it.

At first, graphite was used in its raw form, cut manually, shaped into thin sticks, and inserted into the wood. This process was primitive and lengthy. Therefore, people kept on searching. Almost simultaneously, around 1790, Viennese builder Joseph Hardtmuth and Frenchman Nicolas-Jacques Conté discovered how to make pencil lead core from graphite and clay fired in a ceramic kiln. And now, back to the present.


Do you know what's typical for the part of the manufacturing plant where graphite leads are born? The floor that shines silvery and is slippery like a speed skating rink. One careless movement and you fell to the ground.

We're in the part of production where there are two essential constituents at the beginning of everything. Graphite and clay. In several operations, their mixture is ground and mixed in special machines until perfect substance homogenization is reached.

The mixture goes straight from the so-called Mixing factory straight to the special pressing machines for cartridges. Thick blocks of the mixture pass under pressure through a special press with holes that create beautifully smooth spaghetti from the mixture.

In the next production step, drying, a lead changes its soft consistency and is becoming to look like the one you're used to.

In this part of the manufacturing plant, it's very hot. Here, leads are fired in huge kilns. In special rotating perforated cylinders, pencil leads are not only fired and hardened, but they're also becoming perfectly straight.

At the end of this process, it seems the pencil lead is complete. It has one surprising quality, though. It doesn't write :). In order for a pencil lead to get its writing properties, it must take a special bath. It's thoroughly bathed in a special mixture of glycerin, oils, fats, and other secret ingredients.

And after the bath? Beautiful, scented pencil lead with everything it's supposed to have is complete!

And what are its other steps? We will talk about the part of the production that smells the most like wood next time.

Have a great summer!

Team Koh-i-noor Hardtmuth



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