Painting & drawing blog
HOW PENCILS ARE GRADED
About the HB Graphite Scale
Many of the most prominent pencil making companies today have been around for hundreds of years and were actually instrumental in the development of the modern drawing pencil. Between them they developed a system for using a graded scale that measured the hardness – or softness – of their pencils. In this post I’m going to take a look at how pencils are graded, and how to choose the right grades (and makes) of pencil for your drawing.
How the grading scale came to be
In one of the world’s most enduring misunderstandings, the ‘lead’ of a pencil never had anything whatsoever to do with elemental lead, but has always been made from graphite which is a crystalized form of carbon. When a large deposit of graphite was discovered in Cumbria in England during the sixteenth century it was mistaken for lead ore: the name stuck because the actual nature of graphite and its distinction from lead was not understood for over two hundred years. Initially the graphite from the Cumbrian deposit was used by shepherds to mark their sheep but by the 1800s a thriving pencil- manufacturing industry had grown up in Cumbria . Here square-shaped pencils made with rods of pure graphite were produced, attempts at extending the limited supply by mixing it with gums, glues and resins having been unsuccessful.
The world’s earliest known pencil! This belonged to a carpenter from the 17th century. Before the invention of ‘graded’ leads, pencils were simply lumps of pure graphite cut into sticks. Photo credit: Faber-Castell
However it was Nicolas-Jacques Conté, the founder of the famous Conté à Paris pencil making company who is often credited as the inventor the modern pencil. By 1785, having no access to the source of British graphite, he had mixed lesser quality graphite with a binder of clay and fired it in a kiln before encasing these rods in a wooden covering. Almost simultaneously the Austrian Joseph Hardtmuth, founder of the Koh-I-Noor Hardtmuth pencil company now based in the Czech Republic was exploring the same method and both men took out a patent on the clay and graphite kiln-fired pencil: Conte in 1795 and Hardtmuth in 1803. Today both companies also claim credit for the mechanized methods of pencil production.
Conté and Hardtmuth probably both discovered that by varying the ratio of graphite to clay, you could produce pencils of varying softness and darkness. The more graphite the softer and darker the pencil, the more clay the harder and lighter the mark you make with it. By the early nineteenth century an early version of what we now call the ‘HB’ grading system had been established. This system was likely based on the English words ‘Hard’ and ‘Black’ whereby ‘HB’ stood for a slightly hard and slightly black pencil. Softer pencils were labelled ‘B’, ‘BB’ or ‘BBB’ and harder ones were ‘H’, ‘HH’ or ‘HHH’. This origin is disputed by the Koh-I-Noor company who claim that the ‘H’ designation was named after their founder Hardtmuth and ‘B’ for their location in Budejovic!
The modern grading system
Regardless, these designations were soon refined into the modern pencil grading system we know in Europe today. Here the ‘HB’ grade is considered to be the middle of the scale. The standard writing pencil like the type we all used at school is about the equivalent of an HB pencil with the same graphite to clay ratio. Soft pencils start with a B and then run through 2B, 3B and so on. Hard pencils begin with H followed by 2H upwards. The softest pencils may have up to 90% graphite to clay ratio, whilst lighter ones may only contain 20% graphite. H pencils will appear a grey colour and B pencils tend more towards a black tone.
Between HB and H is the ‘F’ grade, which is something of a quirky anomaly. The F pencil is thought to have been developed for the Japanese market, where softer pencils are generally preferred. A Japanese ‘HB’ grade was found to be too soft for writing and so the F (standing for ‘fine’ or ‘firm’) was introduced as a writing pencil, and then somehow found a way into the artists’ pencil tin. In fact this pencil isn’t especially fine, but it can be sharpened to a finer point than an HB because it’s about half a grade lighter and has slightly more clay. I find an F somewhat useful as a pencil that’s just a tiny bit harder than an HB, but not as hard as an H.
Variations between ranges, and sets of pencils
Companies don’t all produce the same number of grades within their graphite pencil ranges. The most extensive is probably Staedler, who make pencils ranging from 10H to 12B. Other ranges make a much more limited number – Conté à Paris’s graphite sketching pencils for example runs only from 3H to 6B. You’re very unlikely to want to use all the available grades in a drawing, but whether you’ll prefer a selection of harder or softer pencils depends on what type of work you are doing.
Typically the harder ‘H’ pencils are used by designers – in particular graphic artists – people who do technical drawing and engineers. Artists making fine art sketches are very unlikely to work in the higher H grades. I draw pencil portraits and use a range of grades from H through to 9B: here is my maximum range, using Staedler Mars Lumograph pencils.
The darker and softer the pencil the more of the paper texture it will pick up as you shade and the softer (and possibly less precise) your drawing will be. You can also soften and smudge your shading from B grade pencils, should you want to. H leads will hardly smudge – especially 3H and upwards – whereas all B grades will smudge easily.
If you buy a tin of graphite pencils – nearly always a more economical way to purchase your first set – you will typically get around 12 pencils. A set will often feature either a selection of harder grades (mostly H’s), medium grades (typically 6B-4H) or soft grades (H through to 8 or 9B). You should remember that given the inconsistencies between manufacturers, it may be that a hard H pencil in one range is as soft as a B pencil in another, so it’s really worth doing your research before purchasing pencils to find out whether the range you are interested in runs hard or soft.
Inconsistencies between manufacturers
It’s very important to understand that although all pencil manufacturers utilise the same graded labels from H grades to B grades with HB in the middle for their pencils, there is NO industry standard for exactly how light or dark a shade a pencil designated with any particular grade should produce. You’ll find huge variation in the tones of pencils from different ranges, with some much darker overall than others. Therefore for example a B pencil from one brand can literally give you the same shade as a 5B or 6B in a much lighter range. This diagram compares the ranges of many of the best makes of sketching pencil and you can see how varied and inconsistent the shades are between manufacturers.
Adding further to these discrepancies, many manufacturers have now supplemented their regular ranges of graphite pencils with extra black ranges, with names like ‘Noir’ ‘Nero’ or ‘Onyx’. These are pencils with some carbon added to make them much blacker (however much you load a pencil lead with graphite it will still be a grey colour, not a real black). These pencil ranges will have an HB scale applied to them, even though they are many shades darker than a regular graphite line.
How the HB Graphite Scale relates to the US numerical scale
In Europe, the HB scale is the only system for grading pencils that we are familiar with. In the US however whilst the HB scale is usually used to grade artists’ pencils, other pencils such as writing pencils are graded according to a numerical system. Early American pencil manufacturers were influenced by Nicolas-Jacques Conté who graded his pencils between numbers one and four. The modern US pencil scale still ranks pencils only in the middle range of hardness, rising from #1 (softest) to #4 (hardest). It is generally accepted that the HB scale and the US numerical scale compare like this:
However as we have seen companies vary so wildly in the darkness of their pencils that it’s hard to find any standard equivalence. For example Faber-Castell, another of the oldest and most celebrated pencil making companies in the world, makes very light pencils and consider that their HB pencil equates not to a #2 but to a #2 ½. With a much darker range such as Derwent Graphic pencil a #2 would probably equate to a one of their H or 2H pencils.
Choose the right pencil range and grades for your work
We’ve seen the huge variation in tone between different manufacturer’s pencil ranges. How does this affect the pencils you should choose? Clearly if you want to draw very darkly then you would go for a dark toned soft range whilst if you want to draw more lightly you’ll prefer a harder range. In theory if you liked one particular range of pencils that happened to be very soft and dark but you wanted to draw more lightly, you could select pencils at the ‘H’ range of its scale rather than the ‘B’ range. This review of drawing pencils assesses all the celebrated pencils on the chart above and tells you which grades they are available in, how hard or soft they are, and what they are like to work with.