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Understanding Your Materials

Understanding is a beautiful, and usually beneficial thing. On our journey for art knowledge, and as we study and practice the Art Fundamentals, we should make a point of understanding the materials we use. That is the goal of this article about the pencil grading scale. Even a basic grasp of the many factors that determine the quality and grade of our materials—such as graphite pencils and charcoal—will improve our skill in using them.

A basic knowledge of your materials’ origin, history, composition, grades, characteristics, and form varieties will improve your drawings and inspire a deeper appreciation and understanding for your art craft. Understanding which grades of graphite pencil to choose as we create a still life or a portrait allows us to make drawings with confidence and access the full range of values needed for our projects.

Frequently Asked Questions About Graphite Pencils

Some of the most frequently asked questions about graphite pencils are related to graphite itself (what is it, anyway?), the pencil grading scale, what the numbers and letters on pencils mean, how to sharpen pencils, when and where the pencil was invented, how pencils are made, why graphite sticks are called “lead”, and the safety of using graphite (can one get lead poisoning from pencil lead?).

I want to give you a heads up here that this is a more technical subject. I’ve tried to keep it succinct, clear, and interesting without adding too much fluff or going into information overload, but facts based in science don’t lend themselves to word artistry or prose so hang in there with me, ok? Besides, it’s the information we’re after so our improved understanding can begin to shine through our art.

So, let’s dig into the science, history, life, making, and safety of pencils so we can answer as many of those questions as possible.

The Science—What is graphite?

Graphite is a naturally occurring form of crystalline carbon, and the most stable form of carbon. Graphite is a mineral, and its extreme properties (extremely soft, extremely heat resistant, etc.) give it a wide range of uses in metallurgy and manufacturing. It is highly conductive for heat and electricity, and flexible but not elastic, which make it useful in electronic products like batteries. Graphite is primarily used in pencils and lubricants.

Graphite is composed of flat sheets of carbon atoms stacked on top of one another, which slide apart easily because the bonds between them are weak. This means natural graphite has incredibly low hardness, so when we drag our graphite pencil across paper those flat sheets of carbon are left behind and create a mark.

A Mark Maker: The History of Graphite

In a place called Borrowdale, near Keswick in the Lake District of England, a large deposit of graphite was discovered by locals after it was revealed by a storm in the 16^th century. Due in part to its resemblance to lead in color and appearance—and the infant state of relevant sciences like Chemistry and metallurgy at the time—the substance we know to be graphite was at that time named plumbago (Latin for ‘lead ore’) because it was believed to be a form of black lead rather than carbon.

For many years, the graphite deposit in Borrowdale was the only large source of graphite, which gave England a monopoly on graphite sticks. Trade embargos during the 18^th century Napoleonic Wars forced the French Republic to come up with their own version of the graphite sticks that did not rely on imports.  French army officer, painter, chemist, and balloonist Nicholas Jacques Conté had the idea of mixing powdered graphite with clay and water, and then firing the mixture in a kiln.

Conté’s innovation ended England’s monopoly on pencil production, and he continued to develop his manufacturing process by varying the quantities of clay and graphite to change the hardness of the graphite core. Conté’s experimentation and refinement of his process lead to the range of graded pencils we enjoy today, which use the alphanumeric grading scale we’ve become familiar with.

Graphite Pencil Grading Scale Explained

I have never been a fan of standardized testing, but I liked those spiffy #2 pencils. You know you have a maker’s heart when freshly sharpened pencils make you smile, but I digress. When we were filling in our answer bubbles on those tests, we were unwittingly being introduced to the middle of the graphite pencil grading scale.

The #2 pencil is part of the American system for grading “lead” hardness, and it corresponds to the HB pencil on the European grading system. HB is the middle grade pencil, meaning that it contains equal parts graphite and clay for a balance of softness and harness.

The Alphanumeric Scale

Now let’s talk letters and numbers so we can understand this alphanumeric system. The letters used are “H”, “F”, and “B”.

“H” stands for hard; “F” stands for fine, because it can be sharpened to a fine point; and “B” stands for Black.

Higher numbers in front of the “H” mean a harder pencil, while a higher number in front of the “B” means a softer pencil. The harder the graphite core of the pencil, the lighter the mark it makes, and the softer the core, the darker the mark.

Together the numbers and letters create the alphanumeric system used to describe the pencil’s hardness or softness, also called a grading system. This system refers to the ratio of binder to graphite present in the mixture of the pencil’s graphite core, commonly called “lead” (a persistent misnomer, as there is no lead in graphite pencils). The variety of ratios for this mixture is what Nicholas Jacques Conté innovated, and it is what gives us the 24 graphite pencil grades—and full value range—we enjoy today.

The harder the pencil (the “H” end of the scale), the more clay is present in the mixture recipe. Graphite, not clay, is the mark maker of this mixture, so less graphite means less mark making material is present. Marks by pencils from the “H” side of the scale will stay on the lighter end of the value scale.

The opposite is true for the “B” side of the grading scale. The more graphite is present in the mixture, the softer the graphite core will be. More graphite means more mark making material is present in the pencil, keeping marks from “B” pencils on the darker end of the value scale.

Graphite Pencil Grading Scale

How the mixture of graphite powder and clay powder are formulated determines a pencil’s “lead” grade. Below are the charts for both the European and American hardness grading systems.

European Grading System (alphanumeric):

Harder Graphite Core = Lighter Marks

10H ◀ 9H ◀ 8H ◀ 7H ◀ 6H ◀ 5H ◀ 4H ◀ 3H ◀ 2H ◀ H ◀ F

Middle Grade = Balanced

F ◀ HB ► B

Softer Graphite Core = Darker Marks

B ► 2B ►3B ►4B ► 6B ► 7B ► 8B ► 9B ► 10B ► 11B ► 12B

American Grading System (with corresponding equivalents to European System for clarity):

#1 – B

#2 – HB

#2 ½ — F

#3 – H

#4 – 2H

The American grading system is much more abbreviated and appears to have been conceived primarily for pencils used for general writing and drafting purposes. The more expansive, full range of values of the European grading system is preferred and used by artists.

Binders

As you begin learning about artist materials, you’ll hear the term “binder” mentioned, especially when discussing paints. Binders, or binding agents, are substances or materials used to hold or bring together other materials so a cohesive whole can be formed to create the tools and surfaces we use. Binders are part of the mixture (or recipe) for creating art materials, such as graphite and charcoal “leads” and sticks, pastels, paints, etc.

Binders are often liquid, powder, or dough-like substances that bind other materials together through mixing and then hardening via a chemical or physical process. In the case of artists’ materials, binders are used to hold together pigments and other materials—like graphite powder—used to create the tools and supplies we need for our art-making.

Binding agents include materials like wax, linseed oil, natural gums, proteins (egg white or casein), and clay—which is the binding agent for graphite “leads” and is usually a mixture of calcium bentonite and kaolin.

When the world was younger, materials like egg, wax, honey, lime, casein, linseed oil, or bitumen were mixed with pigment by artists to form paints. From the Middle Ages through the early 16^th century, egg-based tempera was a popular binder in Europe. Oil and acrylic polymer have been the binders of choice for paint for quite some time, with oil beginning in 15^th century Belgium and acrylics getting their start in 1953 (aww, like a baby paint compared to oils!).

A Pencil’s Life: Making Marks and Keeping Its Edge

The grade of pencil leads affects not only our choices about their use in our work, but also how frequently they must be sharpened, their smudge resistance, strength, smoothness, and pigmentation. Harder pencils retain a point longer and require less sharpening, while softer pencils lose their point faster and require more frequent sharpening. So, if you have a drawing with a lot of dark and velvety blacks, you are likely to run through your softer leads much more quickly.

On the flip side, while softer leads do require more frequent sharpening, they also offer a softer and smoother application on your surface. Comparatively, harder pencils can feel a bit rougher and scratchy, but they’re helpful when you need lighter values.

Drawing Further: Journey to Modern-Day Pencils

There is a bit more history involved to bridge the timeline between the Conté process and the pencils we use today. When it comes to whose idea it was to place the graphite core between to half-cylinders of wood, I have found competing information. Some sources say Conté had the idea, while others say the addition of a wooden casing was first conceived by an Italian couple by the names of Lyndiana and Simonio Bernacotti.

If it was indeed the Bernacottis, that would mean many of those British sourced graphite sticks were finding their way into rudimentary wooden casings as early as the 1560s. Conté, on the other hand, received a patent for his invention in 1795 and formed La Société Conté to produce his pencils. That is a time gap of over 200 years, but I imagine the truth is somewhere in the middle.

Regardless, the pencil manufacturing process has evolved over time to use the wooden casings we’re familiar with and to include the range of 24 leads so helpful to our art.

How Pencils Are Made

It is during the early stages of the manufacturing process that a pencil’s degree of hardness is determined. The first stage in making graphite pencils is to create a mixture of graphite powder, clay, and water. The variation in the degree of hardness (the graphite to clay ratio) is what gives us so many grades of graphite pencils, most commonly ranging from 9H to 9B in a set.

As I mentioned earlier, softer and darker graphite pencils are created when the mixture contains increasing amounts of graphite; hard grades are created when the proportion of clay is higher than that of the graphite powder.

Making the “Leads”

Once the desired mixture is created it is then pressed through a machine to create the cylindrical core shape (“lead”) and cut to a consistent length before being set to dry. Once dry, the leads go through a firing process and then on to a wax bath. Before the pencils are complete, the wood that will create the casings must go through its own process to be ready to hold the leads.

Making the Wooden Casings

To become the casing for graphite “leads”, pre-cut wooden slats have grooves machine milled into them. Glue is applied in the grooves, the leads are then inserted into the grooves, and a second milled slat with glue is applied on top to close the “slat sandwich”. These “slat sandwiches” are then placed into a large drying wheel before being sent through another machine to mill (cut) the individual pencils from the sandwiches.

The pencil cylinders are available in multiple shapes, such as hexagonal, circular, and rounded triangles. The hexagonal shape is the most common casing shape and keeps pencils from rolling off our desks.

The next step is to paint and stamp the pencils. Paint is mixed and each pencil receives a coat of it through a lacquering head machine before being stamped, dipped, and finally set to dry in a drying room. The finishing process for pencils involves a series of quality tests, including withstanding pressure, sharpening, and visual inspection before packaging.

The pencil making process I have been describing here refers to artists’ drawing pencils. The process is largely the same for standard writing pencils, like the #2 HB pencil, but there are a few differences. Primarily those differences involve the additional step of attaching a ferrule and eraser to one end of the pencils through a rubber tip assembly machine.

Here are a couple from FaberCastell USA, Insider, and NPR’s Skunk Bear of videos that illustrate the pencil making process:

Some Fun Bits About Pencils

It is important to understand our materials, but there’s no reason we can’t make it fun, right? Here are some fun tidbits I found about pencils, their history, and people who have used them:

The average pencil can draw a line 35 miles long, write about 45,000 words, and be sharpened 17 times.

Graphite’s ability to leave marks on paper and other objects is what earned it its name, which was given by German mineralogist Abraham Gottlob Werner in 1789.

Graphite comes from the Ancient Greek γράφειν (“graphein”), meaning to write or to draw.

Breadcrumbs were used to erase mistakes before erasers were invented.

The average size Cedar tree can be used to make about 300,00 pencils.

Pencils have been to space! They can write in zero gravity and have been used on space missions by astronauts.

Pencils can write underwater! (I’m skeptical, but it sounds cool)

Henry David Thoreau used to design pencils at his father’s pencil factory.

Thomas Edison liked to use specially made pencils that were shorter and thicker, 3 inches instead of the standard 7.5 inch size.

Hymen Lipman was the first person to attach an eraser to the end of a pencil on March 30^th, 1858. Bye-bye breadcrumbs!

The darkest grade of artist’s graphite pencil is 12B, while the lightest is 10H.

Ernest Hemingway recommended writing fiction with a pencil because it “gives you one-third more chance to improve it [your writing].”

John Steinbeck and Ernest Hemingway both wrote their novels in pencil first.

The Best Lead Grade: Choosing Graphite Pencil Grades for Drawing

Now that we’ve familiarized ourselves with some of the science, history, life and making of graphite pencils, it’s easier to understand how and why pencil marks behave as they do on paper.

“H” pencils are quite smudge-resistant because they contain more binder than graphite powder. This means they give cleaner lines and makes them helpful for lighter toned work such as technical drawings, outlines, light sketching, and under-drawings in preparation for painting. One tradeoff is their increased scratchiness the further up the H scale you go, but this can be remedied by pairing them with middle grade (F and HB) and B pencils.

“B” pencils are amazingly smooth to draw and write with. Their higher graphite to clay mixture means they smudge easily, but their marks are generally just as easily erased. Their softer nature offers artists the ability to make more expressive and brush-like marks, especially from the higher end of the B scale.

This knowledge and understanding helps us make decisions about which grades of graphite pencils to choose for our drawings.

If the goal for a drawing is to illustrate a frozen tundra in the arctic on a sunny day, the soft and dark leads won’t play much of a role in that project because the scene calls for light tones—and light tones are achieved with hard and middle grade pencils, not soft ones. Of course, the opposite is true for a scene with a clandestine meeting—the cover of darkness is best drawn with soft, B graded pencils.

I recommend having a set of 24 graphite pencils so you have the full value range available to you. It’s best to choose tools that serve the goals and stories of your art, rather than trying to make the story fit the supplies. Here are a couple of examples from my portfolio to give you an idea of what you can do with a full set of graphite pencils (or “leads” and a lead holder), tons of practice, and a healthy dose of patience.

Beyond the needs of your project, the other considerations primarily revolve around your own preferences, workflow, and budget. In my Drawing Tools & Materials for Beginners post, I discuss my recommendations for the supplies beginning artists need to practice the fundamentals of art. Still, at the start, a lot of practice sketches and finished drawings can be accomplished with a simple sketchbook, a pad of quality drawing paper, and a full set of drawing pencils.

Again, having tools that give you access to the full spectrum of values is incredibly important; after that, it’s a matter of tons of mileage and practice. Once you commit to that, nothing can stop you.

Safety & Toxicity: Can One Get Lead Poisoning from Pencil Lead?

The short answer is No. It’s impossible to get lead poisoning from graphite pencils because they contain no lead. Graphite and lead are chemically and atomically completely different substances and are only slightly similar in appearance—but even visually they are clearly different, as you can see below.

Graphite pencils are usually classified as nontoxic because graphite is a minimally toxic carbon-based substance when swallowed or drawn onto the skin. So, when you accidentally poke your hands with your sharpened pencil, you won’t be poisoned or infected by the graphite—but, as with any injury, you should immediately clean and tend to the affected area.

The biggest danger with pencils lies in where you poke or stab yourself (or someone else, but…let’s avoid stabbing people, shall we?) and how severely the resulting injury is. If you somehow are stabbed with a pencil forcefully enough to draw large amounts of blood, the bleeding and severity of the wound is a more immediate concern than the presence of graphite and immediate medical attention would be necessary.

Avoid having pencils (or any other tool) anywhere near your eyes, mouth, nose, and any other sensitive body part or orifice. It’s never a good idea to insert or ingest foreign materials, so if you tend to fidget please get a fidget toy instead of chewing on your pencil!

Working with graphite powder, rather than pencils, can get a little dicey. Powders and dusts always come with inhalation and respiratory risks, so when using graphite powder as a medium be sure to wear a simple mask or face covering and keep your workspace well ventilated. Inhalation of graphite powder can cause irritation to the respiratory tract, coughing, shortness of breath and black sputum.

Long term or chronic exposure to graphite powder has been associated with the development of a lung disease called pneumoconiosis. Ingestion of large amounts of graphite powder may cause gastrointestinal irritation.[1]

Basically, graphite pencils and powder are safe to use and minimally toxic so long as you don’t eat, inhale, or seriously stab yourself with them. Getting a bit of graphite onto your skin while you work won’t harm you at all, but do be sure to wash your hands when you’re done working.

Hey, look! You’re still here, and we’re done! Thank you for hanging in there with me. I know this topic was more technical, but I hope I was able to keep it interesting and answer your questions about graphite pencils, the pencil grading scale, and the safe use of pencils. If you have any questions or feedback, please let me know in the comments below.

Further Reading

The History of the Pencil by Pen2Paper

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[1] http://www.physics.purdue.edu/primelab/safety/MSDS/graphite%20%20-%20Mega%20Graphite.pdf