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Excerpts
from ART HARDWARE: The Definitive Guide to Artists’ Materials, by Steven
Saitzyk © 1987
There are two forms in which
carbon is commonly found in nature: crystalline and amorphous. The crystalline
form has two further divisions. One type of crystal involves six carbon atoms,
which combine to form a ring. Carbon rings of this type tend to arrange
themselves in sheets, which slide easily over one another. They are so slippery
that this crystalline, form is often used as a lubricant. When the first natural
deposits of carbon were uncovered they were mistaken for lead and named plumbago,
or black lead. After many years of use as a drawing material, it was discovered
that the substance was not lead and the name was changed to graphite, from the
Greek word graphein, which means "to write."
In the second form of
crystalline carbon, the carbon atoms link together to form a rigid structure.
This structure results in a highly transparent and very hard crystal, which
cannot be used as a drawing material. This type of crystal is a diamond.
There are four kinds of
amorphous carbon- charcoal, lampblack, coal, and coke. Charcoal is. an impure
form of carbon and is obtained through the incomplete combustion of plant
matter, wood, or bone. Lampblack is obtained by collecting the soot from the
burning of oil. Coal and coke are mined and are not workable as artists'
materials. Carbon black is a term used to describe any intense black made from
amorphous carbon that has been divided into fine particles. Soot has some of the
most finely divided particles known. The smallness of these particles is what
gives Such subtlety to the ink paintings of the Orient. The particle size can be
varied during production to create various effects. Another interesting fact is
that charcoal can be turned into graphite at 5400°F.
 Charcoal
Charcoal is the carbon-rich
residue of incompletely burned wood, bone, or vegetable matter. Artists'
charcoal is made by heating wood in a chamber or kiln without air. This process
produces a piece of charcoal that makes a uniform black line.
Vine Charcoal
Vine Charcoal is produced by
burning sticks or twigs of wood in a kiln without air. Some manufacturers shape
them to produce sticks of a more uniform appearance. Willow is the wood of
choice, because of its even consistency and fineness of particles; however,
linden is more commonly used. Vine charcoal is available in soft, medium, and
hard consistencies.
Vine charcoal is easily
removed by dusting and by erasure. This makes it ideal for preliminary sketches
for oil painting where changes are frequently made before the final outline is
completed. Before painting begins, however, the charcoal sketch must be fixed to
the canvas or the paint will pull the charcoal off the surface and mix with it.
It is best to use a retouch varnish to fix the sketch.
Compressed Charcoal
Compressed Charcoal is
available in round and square sticks. The charcoal powder is mixed with a gum
binder and compressed into sticks. The amount of binder that is used regulates
the degree of hardness, which gives a wider selection and greater consistency of
quality from stick to stick. Several degrees of hardness-HB, B, 2B, 3B, 4B, and
sometimes 6B-are available. Sticks of compressed charcoal do not break or erase
as easily as vine charcoal. Vine charcoal has an irregular shape that does not
allow the edge to be used for broad strokes, but compressed charcoal sticks are
ideal for this.
Charcoal Pencils
Charcoal Pencils are made
from compressed charcoal. The charcoal is protected with wood, or a paper
wrapping, which is the only real advantage of the pencils. The covering helps to
keep your hands and your working environment clean while drawing: it also
reduces breakage and permits by sharpening to produce a point. In the
paper-wrapped version, the charcoal is exposed by peeling rather than by
sharpening. The pencils are available in the same general range of degrees of
hardness found in compressed charcoal sticks, and are classified as extra soft
(96B), soft (4B), medium (2B), and hard (HB). They are best used for making
smaller, more tightly rendered drawings, which require greater control, or for
adding detail.
Carbon Pencils
Carbon Pencils are made from
lampblack, which is purer than charcoal and is therefore more consistent in
quality. This consistency is maintained throughout the available range of
degrees of hardness, which is generally identical to that of compressed
charcoal.
 Graphite
Graphite was used as a
marking tool by the Aztecs long before Columbus went on his Caribbean cruise.
Europe did not discover graphite until 1400, when it was found in Bavaria and
promptly mistaken for lead. The substance was not called graphite until 1789.
The purest deposits of graphite ever found were discovered in Cumberland,
England, in 1564 and were in continuous production until 1833.
The advantage of graphite
over charcoal is that it is less dusty and naturally adheres better to a ground.
It can easily be fashioned into a variety of writing and drawing instruments,
which can be used to express great detail and subtlety. Graphite is also more
easily fixed to a ground and in general has a more durable surface.
Graphite Sticks
Graphite Sticks are
relatively new. Originally, graphite was sold in pieces for marking stone. Later
it was shaped into sticks, which resembled today's artists' graphite sticks.
Today's sticks, however, are not pure graphite, but mixtures of powdered
graphite and clay, which has been fired at about 1900. The amount of clay
present determines the degree of hardness; the more clay, the harder the stick.
A narrow range-2B, 4B, 6B-comprises the available degrees.
The Pentalic Corporation has
imported a graphite stick that has a heavy resin coating. It is called the
Woodless Pencil and is 'a-inch round, as opposed to the rectangular graphite
stick. The Woodless Pencil is available in HB, as well as 2B, 4B, and 6B, and
can be sharpened easily in an ordinary pencil sharpener. Of course, the edges
cannot be used for broad strokes, as can the edge of the uncoated rectangular
stick.
Graphite Pencils
Graphite Pencils are the most
common writing and drawing tools today. In Latin pencillus means "little tail"
and describes a small brush used in medieval times for drawing with ink. The
term "pencil quill" is still used sometimes to describe a type of small pointed
brush used for signmaking and graphic arts work. In some cultures, the word
"pencil" is still used to refer to a small brush. It would seem that the
graphite pencil derived its name from the fact that it has a wooden handle, like
a brush, and a small tip that can be fashioned into a point.
The first graphite pencils
were blocks of graphite that were shaped into sticks and wrapped with string.
Since graphite was at first mistaken for lead, they were called lead pencils.
Soon after the discovery of the graphite deposits in England, it became clear
that the amount of available graphite was limited and conservation measures
rapidly followed. Several attempts to extend powdered graphite with gums,
resins, and glues, which were pressed into blocks of grooved wood, had only
limited success.
The invention of the modem
pencil has been credited to Nicolas-Jacques Conte, a French scientist under the
commission of Napoleon. In 1795, he developed a manufacturing process of
roasting a mixture of clay, purified graphite, and water in a kiln, and then
encasing the substance in wood. Soon after, Joseph Hardmuth found that the
greater the amount of clay used in the mixture, the harder the pencil point.
This led to the development of the various degrees of hardness of pencils. The
modem process for making pencils involves producing a paste, like that of
Nicolas-Jacques Conte, and partially drying it through filtration. It is then
extruded into long strands and fired at 1900°F. The strands, which are still
slightly porous, are then filled with natural waxes for the purpose of
lubrication and to help the graphite adhere to the ground. They are either
packaged for use in a lead holder or inserted into a wood casing.
Today, graphite pencils are
made in different degrees of hardness by regulating the amount of clay added.
The greater the quantity of clay, the harder the lead and the lighter the
overall drawn line will appear. It is common to have several different degrees
of pencils to vary the detail and the light and dark areas of a drawing. The
more "Hs," the harder the lead. The more "Bs," the softer the lead. HB and F are
intermediate grades between the two types. B through 10H are commonly used in
drafting. 8B through F are preferred for artwork. Writing pencils have their own
hardness scale, which roughly coincides at certain points with the drafting
scale.
SCALE OF DEGREES FOR ART AND DRAFTING PENCILS
8B . . .
4B-3B-2B-B-HB-F-H-2H-3H-4H-5H . . . 10H
<<<softer<<< >>>harder>>>
SCALE OF DEGREES FOR WRITING PENCILS
1(3B)-2(B)-21/2(F)-3(2H)-4(3H)*
*degree within parentheses is
the rough equivalent to the drafting scale
The primary differences
between school-grade pencils and professional-grade pencils are the larger range
of degrees and the uniformity in the manufacturing and performance of the
professional-grade pencils.
There are several unique
graphite pencils such as the Blackwing, which has an oversized eraser; the Negro
Pencil, available in three thicknesses of leads; and the Eagle #314 Draughting
Pencil. All of these are soft drawing pencils that are similar to a 6B art
pencil. Most have slightly thicker leads than the average drafting pencil, yet
are less expensive. Flat sketching pencils have a rectangular shaped lead
enclosed in a similarly shaped wood covering, which is sharpened with a razor or
a knife. They come in a limited range of degrees-2B, 4B, and 6B. All of these
graphite pencils are used primarily for broader, more expressive drawing or for
quick sketching.
 Drafting
Leads and Metal Lead Holders
Drafting Leads and Metal Lead
Holders were developed before the wood graphite pencil. The lead, which is the
same as that used to make graphite pencils, is held in place with a three- to
four-part vise. A button at the top of the lead holder, which acts like a
clutch, is pressed to open the vise and release the lead. Caution must be
exercised to prevent the lead from falling out of the holder. A test of the
quality of a lead holder is to see if the lead slips in the clutch when it is
locked in place. The primary advantage of a lead holder is that the implement
does not get shorter as you sharpen the lead, and a sharper, more tapered point
can be produced with the aid of a lead pointer than can be had with a pencil and
pencil sharpener.
Drafting lead is available in
the same degrees of hardness as pencils. There are also limited selections of
colored lead available, as well as leads designed specifically for the surface
of drafting film. The "E" series of drafting-film leads produces well-defined
lines and less graphite dust on the drafting film.
Mechanical Pencils
Mechanical Pencils were first
introduced in 1822 by S. Mordan and J. I. Hawkins. The first spring-loaded
mechanical pencil was patented in 1877 and a twist-feed mechanism was developed
in 1895. The primary differences between mechanical pencils and lead holders is
that the mechanical-pencil lead is advanced in increments and will not
accidentally drop out, and the lead does not have to be sharpened. Since a vise
is not used to hold the lead, it is free to rotate as a line is drawn so that a
consistent line width is produced. Consequently, the lead is available in four
widths-0.3mm, 0.5mm, 0.7mm, and 0.9mm. The 0.9mm was introduced in 1938 and
led the way for the rest. Today, mechanical pencils are designed to be
self-feeding and several leads can be loaded through the top at one time. The
technology has advanced so that there are mechanical pencils that automatically
advance the lead as it is worn down, eliminating even the need to stop and make
adjustments. These are expensive, however, and are not widely available.
The major disadvantage of
mechanical pencils that use very thin leads is that the leads break easily. The
softer the lead, the more easily it breaks. Some manufacturers impregnate their
leads with a polymer to make them less breakable. But only a narrow range of
degrees-from 4H to 2B-is available.
Excerpts
from ART HARDWARE: The Definitive Guide to Artists’ Materials, by Steven
Saitzyk © 1987
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Carbon-Based
