What is a Pencil made of?
What is a Pencil made of?
Graphite mixed with clay and fired, glued inside two grooved halves of softwood. No lead, ever.
There has never been lead in a pencil. The Borrowdale graphite deposit found in sixteenth-century England was assumed to be a lead ore and called plumbago, "lead ore", and the name stuck through four centuries and several languages. The clay-and-graphite recipe that made cheap pencils possible was worked out by Nicolas-Jacques Conté in 1795, during a French wartime blockade of English graphite, and the ratio he invented still defines the grading scale: more clay gives a harder, fainter H grade, more graphite a softer, blacker B. HB sits in the middle, and the American #2 pencil is roughly the same thing.
Component by component
| Part | Material | Why that material |
|---|---|---|
| core | graphite powder blended with clay, extruded and fired at around 1000 °C | Graphite alone is too soft and crumbly to write with; the clay is a binder whose proportion sets the hardness grade. |
| core treatment | wax or oil soaked into the fired core | It lubricates the mark so the core glides rather than scratches, and stops the graphite dusting off the page. |
| casing | incense cedar, basswood or poplar, in two grooved slats glued around the core | These woods sharpen cleanly across the grain without splintering, which almost no cheaper timber does. |
| ferrule | aluminium or brass tube, crimped | A soft metal can be crimped tight onto both wood and rubber without cracking either. |
| eraser | synthetic rubber or plasticised vinyl with abrasive filler | Factory-fitted erasers are made hard so they survive years in a pencil case, which is why they smudge more than a standalone eraser. |
Other stationery and paper objects
- Paper Cellulose fibres from wood pulp, plus up to a third mineral filler, sizing and brightener.
- Ballpoint pen A tungsten carbide ball a millimetre across, rolling in a brass socket, fed by thick oil-based ink.
- Glitter Aluminium-coated polyester film, colour-coated and chopped into fragments — by definition a microplastic.
- Crayon Paraffin wax with pigment stirred in, poured hot into a mould and cooled. Almost nothing else.
- Cardboard Two flat kraft paper liners glued either side of a fluted paper medium — the flutes do all the work.
- Eraser Either natural rubber with fine abrasive and oil, or plasticised PVC — two different ways of lifting graphite.
- Blackboard chalk Mostly calcium sulfate — plaster of Paris — rather than the calcium carbonate the name suggests.
- Playing card Two sheets of paper laminated around a black glue core, then coated in plastic — or solid PVC.
- Postage stamp Coated paper with phosphor bands, printed in security inks, on either water-activated gum or a self-adhesive.
Common questions
- What is a Pencil made of?
- Graphite mixed with clay and fired, glued inside two grooved halves of softwood. No lead, ever.
- What is the core of a Pencil made of?
- Graphite powder blended with clay, extruded and fired at around 1000 °C. Graphite alone is too soft and crumbly to write with; the clay is a binder whose proportion sets the hardness grade.
- What is the core treatment of a Pencil made of?
- Wax or oil soaked into the fired core. It lubricates the mark so the core glides rather than scratches, and stops the graphite dusting off the page.
Related pages
- Paper Cellulose fibres from wood pulp, plus up to a third mineral filler, sizing and brightener.
- Ballpoint pen A tungsten carbide ball a millimetre across, rolling in a brass socket, fed by thick oil-based ink.
- Glitter Aluminium-coated polyester film, colour-coated and chopped into fragments — by definition a microplastic.
- Crayon Paraffin wax with pigment stirred in, poured hot into a mould and cooled. Almost nothing else.
- Cardboard Two flat kraft paper liners glued either side of a fluted paper medium — the flutes do all the work.
- Eraser Either natural rubber with fine abrasive and oil, or plasticised PVC — two different ways of lifting graphite.
- Blackboard chalk Mostly calcium sulfate — plaster of Paris — rather than the calcium carbonate the name suggests.
- Playing card Two sheets of paper laminated around a black glue core, then coated in plastic — or solid PVC.
- Tennis ball Sport and games
- Banknote Around the house
- Golf ball Sport and games
- Glass Building materials
- Soccer ball Sport and games
- Marshmallow Food and drink
Sources
- Typical range compiled from manufacturer specifications — At One Place