Monday, July 30, 2012

Pencil Not So Basics

Although most of the posts on this blog pertain to digital subjects, having used a pencil for much longer than I've used a mouse, track pad or graphics tablet, I decided to author a post about the pencil. 

Pencil making began in the mid 17th century in Germany, Nicolas-Jacques Conté (1755-1805) was the first to patent the present commercial process for mass manufacturing pencils in 1795 in France. The name Conté should be familiar to illustrators because of the Conté crayon or stick. Conté compressed and fired powdered natural mined graphite, finely ground clay and water to create long thin cylindrical or square rods. The graphite content determined the softness of the pencil while the clay content determined the hardness. The Faber Company, one of the first pencil manufacturers, now familiar to us as Faber-Castell, began producing pencils even before the Conté Process was invented.
Graphite raw material.
Clay raw material.

The Pencil

Using Nicolas Conté’s process, pencils are manufactured in a variety of softness and hardness called “grades”. Although differing from Conté’s, by the end of the 19th century, a number/letter grade system was recognized and is now used by most European and American pencil makers for artist and drafting pencils. And even though there is no lead metal in the graphite in pencils, the grades are also called leads.

The grades are as follows:
9H, 8H, 7H, 6H, 5H, 4H, 3H, 2H, H, F, HB, B, 2B, 3B, 4B, 5B, 6B, 7B, 8B, 9B

Tonal scale of pencil grades.

H stands for “hardness”.
B stands for “blackness”.
F stands for “fine or finest”.
A 9H lead is hardest, producing the lightest mark. A 9B lead is the softest leaving the darkest or blackest mark. Although not documented the F grade most likely began with the German manufacturers where it is “feinste”.

Not All Pencils are Created Equal

Another simpler number system is also in use in the US. It ranges from #1 to #4 with the most common being the #2 pencil with yellow coated wood and an attached eraser, Although the #2 is equivalent to an HB in hardness its best use is for simple handwriting. It is important to note that the quality of these pencils differs significantly from artist and drafting pencils. I have seen many an art student struggling to draw with one of these pencils, only to be limited by its poor quality of graphite/clay mixture and mistakenly thinking a #2 pencil should be darker.

In the Too Much Information Category

An older way of classifying pencil grades was by the use of multiple letters. Primarily used by pencil manufacturers in England, it went like this. Hard pencils were stamped with an HHHH, HHH, HH, etc., while soft pencils were labeled BBBB, BBB, BB, etc.

How to Use Pencil Grades “The Bicycle Analogy”

So now we come to the real purpose of this post. We all know that if we use a light touch, a 4B lead can make a mark equivalent to an HB, or a 2B lead can make a mark as dark as a 6B. So why are there so many grades of pencils? Here’s why.

I’ll use “the bicycle analogy”. Professional cyclist’s bicycles come with a range of gears that allow the cyclist to be most efficient in all circumstances. The goal is to pedal at a steady rate. In cycling its called “cadence”. A cyclist uses a higher gear to get more speed and distance using a consistent amount of energy from pedaling on a level surface. They downshift to a lower gear to go up inclines, which causes a loss of speed and distance but keeps pedaling rate and energy expended as consistent as possible to the level surface situation.

Lead samples.

Now think of pencil grades the same way, except this time instead of pedaling rate, think in terms of the hand pressure used to make a mark. Every artist draws in a way that is natural for him or her. Some artists have a light touch while others are “heavy handed”. The idea is to use the pencil grades to provide the different tone variations in a drawing without having to drastically stray from your natural pressure. So, a heavy handed drawer can have difficulty if they try to use a 3B pencil to get some lighter subtle tones, whereas by switching to an F grade pencil those desired tones can be achieved with ease, and without the need change their natural pressure.

So does that mean an artist always needs to have all 20 grades of pencil at hand? Of course not, however they are at your disposal for nearly any circumstance. Engineers and draftsmen tend to use H grades for mechanical drawing and hand plotting. Illustrators tend to use the B grade pencils, but they can also use H grades to do light preliminary sketching. H pencils can be so light that they won’t disturb the illustration as it proceeds to finish.

How a Pencil Works

It’s obvious and yet it may not be. When you use a pencil to create a drawing, you are making marks on paper by applying some pressure and moving the pencil across the surface. As you do, lead is transferred from the pencil to the surface of the paper. The pencil begins to wear down because you are using the lead to create an image. So that’s the obvious part. What is not so obvious is that while you are moving the pencil across the surface of the paper, friction is created by the movement of the pencil, heating up the tip of the lead. The faster you move the hotter the tip becomes, so when you are blackening in a large solid area or hatching, the tip of the pencil heats up. The heat actually hardens the tip of the pencil, which in turn causes the pencil to resist transferring lead to the paper surface. Alternatively, the pencil tip, which is now harder, begins to “burnish” or polish the graphite that is on the surface of the paper, so dark dense areas begin to shine.  The heat can also warp the surface of the paper depending on the paper structure. And, if you want to darken the darks in a your drawing, paper accepts graphite better than graphite accepts itself, so it is difficult to layer graphite over an area where the surface of the paper is saturated with graphite. It’s best to use a soft grade pencil to apply dark graphite to the paper rather than trying to go over a dark area to make it even darker. (More on paper in a future post.)

Closeup example of pencil work burnishing itself and warping the paper.

One Last Thing

Have you ever been frustrated when sharpening a pencil, only to find that when you take your pencil out of the sharpener, the tip is broken? So you repeat the sharpening, only to find yet another broken tip, and so on. The natural inclination is to blame the sharpener, but it could actually be the pencil that’s to blame. It’s fairly easy to damage a pencil. If you drop one, it may look just fine, but the impact could have cracked the lead inside of the wood sheath. Much the same as when a carton of eggs is dropped. The carton looks just fine, but the eggs inside are broken. And who’s to say how the pencil had been treated during shipping or by the retailer. If this happens it may be time to switch to another pencil.


The point of the story, no pun intended, is to consider which pencil grade is appropriate for a desired effect and frequently sharpen your pencil. You can also rotate the pencil tip to expose fresh lead. By sharpening and rotating you will allow fresh exposed lead to transfer to the paper and also improve the line and tone quality of your drawing.