What is pencil lead made of & where does pencil lead come from? These are the questions you start pondering in the middle of a too-warm afternoon when you’re sitting at a desk with a pencil in your hand, working, when you’d rather be anywhere else but there.
In this guide, we are going to cover what material pencil lead is made from, where they get the raw materials to make pencils and how they make pencil lead. We will also dive into what colored pencil lead is made from as they use different materials to make colored pencils.
Table of Contents
1. Where Does Pencil Lead Come From
Pencil lead does not come from lead it is made from graphite. Even though it’s greasy and black and soft like lead, it is actually a carbon material called graphite. Did you know that the biggest pencil in the world is 76 feet long with a 10-inch lead core that weighs 4,500lb.
2. How is Pencil Lead Made
Graphite is mined as flakes or lumps and ground together with clay, then baked into the little sticks you see encased in wood or inside mechanical pencils. This is the main reason why the pencil lead is not poisonous.
(Check out this video from pencil maker Faber-Castell showing how pencil lead is produced. Pretty cool.)
3. Where Does Graphite Come From
Graphite (pencil lead was first discovered in the late 1500s in Borrowdale, in northern England’s Lake District. Supposedly, a storm blew over some trees and exposed a dull black material that the locals began using to mark their sheep. Word spread of the find, and eventually, people discovered they could cut the material and form it into sticks with which to write.
The area became a center for pencil making and is now the site of the Cumberland Pencil Museum.
Because it looked like lead, the pencil material was known as plumbago, or lead ore. But, in 1779, chemist Carl Scheele made the discovery that it was a form of carbon and unrelated to lead. The word graphite came from the Greek verb graphein, which means, “to write.” Still, people continued to refer to it as lead.
At first, the Borrowdale deposit was the main source of pencil lead throughout Europe. However, there were deposits of graphite in less solid forms in many other parts of the world. In 1795, a Frenchman named Nicholas Jacques Conté figured out a way to mix clay with graphite powder and bake it in kilns to form pencil lead.
That discovery eventually led to the demise of the pencil factories around Borrowdale because graphite could be so easily obtained elsewhere. Now, according to a report from the U.S. Geological Survey, the largest deposits of graphite are found in China, Europe, The U.S., and Mexico. China is one of the main exporters of pencil leads.
As a matter of fact, Discover Magazine recently reported that:
More than half of all pencils come from China. In 2004, factories there turned out 10 billion pencils, enough to circle the earth more than 40 times. In a bit of irony, Canadian health officials recalled some Chinese pencils a couple of years ago because the pencil coatings were contaminated with….yep, lead.
4. What is Coloured Pencil Lead Made From
As with graphite pencils, there is no lead in a colored pencil its lead is made from other materials. Colored pencil lead is made from a combination of colored pigment, binders, and extenders. Each colored pencil manufacturer has its own specific combinations which are usually a closely guarded secret.
Coloured Pigment – this is what determines the color of the lead, the more expensive colored pencils have a higher quality and purer pigment. These provide more vibrant colors and have better lightfastness.
Binders – These are what holds the pencil leads colored pigments and the other ingredients together to make a solid substance that can be used in the pencil. They also ensure that there is an even pigment distribution in the lead. Depending on the type of pencil and the properties it is required to have, binders can either be wax or oil-based.
Extender Pigments – combined with binders these are used to modify how hard or soft the pencils colored lead is and its texture. By modifying the hardness and texture of the colored lead it affects how the pencil interacts with the paper. In a similar way to graphite pencils but there is no lead pencil hardness scale for colored pencil lead as there is for graphite pencils.
5. Is Pencil Lead Made of Carbon
Pencil lead is made from a form of carbon called graphite this is mixed with clay to make modern-day pencil lead.
6. Is Pencil Lead Flammable
Pencil lead is not flammable as it is made from a combination of graphite and clay. If pencils were made purely from graphite, then you would still need a heat source in excess of 1000 degrees for it to burn.
7. Is Pencil Lead a Conductor or Insulator
Pencil lead is made out of two materials graphite and clay, graphite is a conductor, and clay an insulator. Therefore, pencil lead is a conductor of electricity but has a high resistance. Softer pencil leads have a lower proportion of clay to graphite and will conduct electricity better. Pencils that have lead grades from 9B -B will conduct better than pencils with HB -9H lead grades.
8. Is Pencil Lead Waterproof?
Pencil Lead is not waterproof but it does have certain water resistance and harder pencil leads are more water-resistant than softer leads. This is partly due to the fact that modern pencils are not only made from graphite and clay but from polymers as well. There is also a difference between the lead in wooden pencils and mechanical pencils. As mechanical pencil lead is not made of the same material combinations like that of wooden pencils.
9. What is the Darkest Pencil Lead?
There are two pencils that have the highest B lead grade and are therefore the darkest graphite pencils these are the Staedtler Lumograph 12B and The Mitsibushi Hi Uni 10B Pencils. Although charcoal pencils will write a darker line than a graphite pencil check out The Complete Guide to The Darkest Pencil Lead for more information.