The Difference between Graphite and Charcoal Explained

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Main difference between the chemical structure of charcoal and graphite:

Charcoal is a matte dark drawing material that crumbles easily and is often used for expressive marks. Charcoal’s structure is that of a complex lattice with no distinct or repetitive design. This lack of uniformity causes it to irregularly fold in upon itself creating many little dips and craters within its structure and a vast surface area. This pore structure enables it to be used in scientific processes as a filter as, depending on the conditions in which the charcoal is produced, the craters can form at different sizes allowing them to adsorb specific molecules (much like a sieve). This lack of uniformity also causes it to be very fragile and fracture oddly on a molecular level, resulting in a dusty, crumbly, matt material that gets caught in the tooth of the paper but can be easily wiped away if it is not fixed in some way. Charcoal’s flakey texture enables artists to create a vast array of textures from a dense line when pressure is applied as lots of particles are being deposited to a much gentler, powdery line when less pressure is used and the particles are spread out or more diffused. The molecular structure also informs it’s application – drawing with charcoal feels rough and slightly catchy because on a molecular level the charcoal is fracturing irregularly.

Graphite is a slightly shiny material, usually in a grey that is used commonly in pencils and sticks for most writing and drawing applications. Graphite in contrast produces far less dust when being used and adheres to surfaces easier without much need, if any, for fixative. This is because of graphite’s uniform, layered structure as shown above. While the atoms within each layer are bonded very securely, resulting in very stable sheets of graphite, the bonds between the layers are weak, allowing the stable sheets to slip and slide easily over one another (imagine a box of dry lasagna sheets). When drawing with graphite the layers easily slip off one another, and therefore off the pencil, allowing the tool to glide effortlessly across the paper leaving perfectly structured sheets of graphite behind. This explains why graphite is less crumbly than charcoal, produces smoother, less dusty marks and is easier to control – although graphite sheets separate from one another they will maintain their uniform structure, whereas charcoal will fracture into irregular shards. Graphite has a slightly shiny appearance and is a dull grey colour – as it is unreactive, it can also be mixed with pigments to create coloured graphite pencils.

A fascinating fact that proves how closely related these carbon allotropes are is that if you heat charcoal to 2982 degrees Celsius, it turns into graphite!

Everything You Need to Know about Charcoal:

Charcoal is one of the oldest art materials ever used. The first recorded use are cave paintings that date back from 23 000 BC. Since then various technologies and methods have been invented or harnessed to enhance its properties and compensate for its structural weakness.

How is Charcoal made?

Charcoal is made by burning incompletely natural matter such as plants, wood or bone, over a long period of time in a chamber, pot or kiln that has restricted airflow. This leads to the incomplete combustion of the material and production of the form of carbon we know as charcoal.

What is charcoal?

Charcoal is a dry medium that can be used in its raw form as sticks or powder, or mixed with gum or wax binder to make it easier to handle. It can create a wide range of tonal marks from intense matt black to very light greys. It’s structure makes easy to remove from a surface with the brush of a hand, although it can leave some staining due to dust getting trapped in the surface texture, and it can be applied to smooth or rough substrates with ease and the correct amount of pressure.

Types of Artist Charcoal:

The wood, preparation, binders and format dramatically change the texture and application of different forms of charcoal, so this explains the main types of charcoal and their applications.

Vine, Willow and Linden Charcoal:

Vine and willow charcoal are both made by heating actual vines and pieces of willow in a kiln or chamber. These sticks tend to be fairly thin and long and are always slightly irregular restricting some of the marks you can make. The different wood produces a different charcoal with vine charcoal creating a dark grey and willow charcoal creating a rich, deep almost velvety black.

Willow charcoal tends to have a more uniformed, consistent mark and finer particles than vine charcoal. It is available in a range of widths, usually named thin, medium, thick and chunky or jumbo. These vary between 3 to 24mm. Often the willow used for artist charcoal grows quickly and only needs a single growing system. The sticks are usually heated over a period of 3 days to make them suitable for artistic use.

Vine charcoal tends to be easy to dust or erase making it perfect for life drawing, quick sketches or compositions that need constant reworking. Vine charcoal is also available naturally in a range of hardness including soft, medium and hard.

Linden is also a wood commonly used to create stick charcoal. It is also possible to make charcoal yourself using ovens that are on for a long time at a high temperature with a completely sealed casserole dish or similar however this is a fairly lengthy and involved process.

Charcoal Powder:

Powdered charcoal is literally charcoal in powdered form. It can be made by crushing up the dust of willow or vine charcoal or be bought as a separate product. It can be combined with other charcoal products or used wet with watercolour to create areas of dark rich black in artworks. You might find it doesn’t create as dark a mark as compressed charcoal so using a combination of forms in a piece can be useful, however, it can be perfect for toning a whole surface or area of a surface. This can be done by using a variety of sized brushes with dry powder and blowing away excess dust or by mixing the charcoal with a small amount of water on a palette. It is worth practicing if you plan to use wet charcoal as the wrong ratio of water to charcoal can create a muddy effects. Wet charcoal will dry to have the same appearance as applied dry charcoal, meaning you can use multiple application techniques on a work to create a seamless, unified finish. If using wet charcoal you will need a suitable absorbent surface and will still need to fix it as you do with any charcoal piece.

Compressed Charcoal:

Compressed charcoal is now commonly used as it breaks much less easily than vine charcoal and is harder to erase (although some artists will enjoy this quality of the stick variety of charcoal). You can also use the side of the stick to create broad consistent strokes, which is completely impossible while using vine charcoal due to its irregular shape. Compressed charcoal is made by combining charcoal powder with a gum binder and pressing it into sticks, this allows the makers to control the hardness of the sticks by increasing or decreasing the amount of binder. This also affects the consistency (increased from that of the vine) and the shade of each block and stick. The range of hardnesses is fairly wide going from HB, B, 2B, 3B, 4B to occasionally 6B or alternatively referred to as extra soft, soft, medium and hard.

Compressed charcoal also allows larger sticks to be produced than those available as raw material, these can then be sharpened into a point and are less messy due to the binder than raw charcoal. Allowing a new range of marks in deep black or subtle more controlled gradations.

Charcoal Pencils:

Charcoal pencils are made by putting compressed charcoal (so charcoal powder and a gum or wax binder) into a wooden jacket or very occasionally into a paper jacket similarly to a grease pencil. The most common wood used for the jacket of charcoal pencil is cedar. This development for charcoal makes it perfect for producing fine, clean and crisp drawings that you could produce with graphite pencils but with the added benefit that you can produce very deep black matte areas and shades that do not have a shine.

An advantage of charcoal pencils over other charcoal forms is there is a much lower chance of breakage and they are easy to sharpen to a point, for the paper wrapped version you peel away rather than sharpening but you can use a sandblock to shape the tip. Both types of charcoal pencil allow you to use charcoal pencils to make tiny, considered and accurate drawings with a lot of control and potential for minute detail.

They are found in the same variety of hardnesses as compressed charcoal ranging from extra soft to hard, also referred to as 6B to HB.

The combination of charcoal and graphite pencils can enhance a drawing by playing both with tone and with the matte and reflective surfaces of each. Some portrait artists will use graphite for the hair, eyes and accessories and then charcoal for delicate soft skin tone and for softer more luxurious fabrics.

Miscellaneous ‘Charcoal’ Drawing Materials:

White charcoal:

Some white artist pencils are referred to as white charcoal however they have no relation to traditional charcoal and in fact contains normally titanium white pigment or calcium carbonate and a clay binder or alternative binder inside a wood sheath. White charcoal does legitimately also exist, it is a Japanese variety also known as ‘Binchōtan’. This charcoal is a lot lighter than traditional charcoal but is more of a light grey, ashes colour than white.

Carbon pencils:

Carbon pencils are sometimes mentioned in the same breath as charcoal products, however these are made of a different form of carbon than either charcoal or graphite. They are made with lampblack, a pigment made by gathering up the soot left over from burning oil. They have a more even consistency than charcoal since the material is purer and smoother and they are available in the same variety of hardnesses as compressed charcoal and charcoal pencils.

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Everything You Need to Know about Graphite:

Graphite is one of the most familiar inorganic, yet naturally occurring, materials that artists use, even though in its most common form, the pencil, it has only been used for the last 600 years. The reason we refer to a pencil ‘lead’ is that graphite was thought to be a type of lead until 1779 when a Swedish chemist discovered it was a mineral form of carbon. The term graphite comes from the greek word ‘graphein’ meaning ‘to write’.

How is graphite made?

Modern pencils are made by creating a paste of clay, purified graphite and water that is partially dried through a filtration process. This is then extruded and fired at 1038 degrees Celsius. These porous strands are then soaked and filled with wax allowing a smoother line and better adherence. These are the leads that are typically used in a pencil or a lead holder.

The first appearance of graphite encased in wood dates from around 1565, close to the time natural graphite was first discovered in Cumbria. Other natural sources exist in Siberia, Germany and in the USA. However graphite is now artificially produced by heating cokes (another carbon allotrope) at high temperatures.

This synthetic graphite tends to be less reflective than mineral ‘flake’ graphite, additionally synthetic graphite’s grey hue can be altered by changing the size of the particles that make it up. The shape and size of the particles affect the reflectivity and textural differences of the marks and thus the final piece. This explains the effect of different pencils and how they can be used to build up a piece. It also tends to be slightly more granular and less platy than its natural counterpart and this means it has a slightly different texture when used as a drawing material.

What is graphite:

Graphite is a metallic, grey mineral that is used for writing or drawing. It is a soft yet brittle substance, so unless used as a drawing material in powder form, it requires a protective shell or a binder. It is used mixed with other ingredients to enhance its composition, strength, hardness or hue. Many artists find graphite essential to produce sketches, final pieces and work on final details. It can be buffered, smudged or erased to create different effects and can be sharpened to a very neat fine point or be bought in a soft hardness that can be easily manipulated.

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Types of Artist Graphite:

Like charcoal you can get graphite in many different forms for artistic use. Some of these preference control and detail while others are useful for shading, bold marks, gradiation or quick expression.

Graphite Pencils:

The word pencil comes from the latin ‘pencillus’ that means little tail and originally referred to a small brush used for working in ink during the medieval times. Our modern pencils earnt this name by having a wooden pencil and a small pointed tip like a tiny brush, or ‘pencillus’, would have.

Graphite pencils were originally blocks of raw graphite, mined from the ground, that were shaped into sticks and wrapped with string. Shortly after the discovery of graphite it was clear the amount of naturally occuring graphite was finite leading to people experimenting with combining powdered graphite with gums, resin and glues to extend them. This mixture was then pressed into grooved wood, it wasn’t entirely effective.

Nicolas-Jacques Conte (namesake of the Conte brand) supposedly made the first modern pencil for Napoleon in 1795. This pencil is made by roasting clay, purified graphite and water in a kiln and then putting it is a wood sheath. Joseph Hardmuth, then improved the technique by discovering you could change the hardness of the pencil by varying the amount of clay used.

The degrees of hardness that apply to artist pencils are completely down to the amount of clay added. The more clay the harder the lead is but the lighter the overall line. You can use these different hardnesses to create detail, change the appearance of line or create dark and light areas. Artist graphite pencils are measured in hardnesses between high Hs the hardest and high Bs, the softest leads. F or HB is seen as the neutral hardness of pencil, in general artists will use 8B to F but this is dependent or what effect the artist desires or needs.

Graphite Blocks and Sticks:

While our modern graphite sticks are fairly new, graphite was originally sold in pieces for marking stone and sheep. Later it was shaped into sticks, which resembled today’s artists’ graphite sticks. Today’s sticks, however, are not pure graphite, but a mixture of powdered graphite and clay that has been fired at a very high temperature. The amount of clay present determines the degree of hardness; the more clay, the harder the stick. The variety of hardnesses is a lot smaller than that of pencils, ranging between 2B and 6B. Graphite sticks come in a range of sizes varying from a block or to ones mimicking the shape and size of a pencil, which you can use a sharpener with. Brands of ‘woodless pencil’ are also made using a similar procedure but with a heavy resin coating around the outside that needs to be sharpened away like you would with a standard pencils. One of the advantages of graphite sticks is you can create broad strokes, rubbings and distinctive dark lines easily.

Graphite Powder:

Graphite powder, which is often a by-product of the manufacture of synthetic graphite for other purposes, can be used similarly to charcoal powder and can be an interesting as well as very useful material. You can use it wet or dry and apply it with a variety of brushes to get different effects. If used with water you can apply it in washes similar to that of ink or watercolour. This makes it great for toning areas of a surface in preparation for a sketch allowing you to work in highlights quickly using an eraser on a consistently toned sheet. You can also use smaller brushes to add fine details. Another alternative is to apply using a tissue or a small piece of leather all these methods will give the work you create a completely different texture. It is also particularly useful for knocking back highlights by applying it dry, gently to a whole piece without disrupting details. Be aware however the more you rub it the shiny and ‘polished’ the whole surface will become as it buffs the particles.

Graphite and charcoal are both exciting mediums in their own right, combining both of them and the vast array of formats they are now available in allows you to find the best working method and set up for you. Paying attention to the different formats they come in, each products hardness and tone means you can often solve a problem you’ve been coming up with in your sketching and drawing by simply introducing a new form to your working collection, whether this is wet graphite powder to get a neutral tone as a ground, a carbon or charcoal pencil in a graphite drawing to get deep, rich dark tones, a hard graphite stick to add metallic details or the humble vine stick to outline your oil composition.

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