Sculpture
Materials and Methods
Armature
Once the artist has an idea of the sculpture's
composition and before an artist can build the sculpture up
with clay there must first exist a solid support to which the clay will be
applied. This is especially important when the sculpture has an open composition
with outstretched limbs. This solid support is called an
"armature."
Clay
can be very heavy and for a life size adult figure can easily weigh 600
pounds. This mass must be internally supported by a solid framework, usually
welded pipe and wire, mounted securely on a modeling board. The size and
shape of the armature is dictated by the size and complexity of the sculpture. In
preparation, an artist will often prepare a small clay or wax model of the
future sculpture called Maquette which will lack detail but aid in deciding
composition and the resulting construction of the armature. If the armature is not
constructed properly or if the artist changes his mind about the composition
after the work has begun,
the completed sculpture may have pipes sticking out of the surface and
the work must be torn down and the armature rebuilt correctly before starting
again. This is not an uncommon occurrence even with the most experienced
artists.
Types of Modeling Material (wax, water clay, oil
clay)
Wax. A specially formulated modeling wax has advantages
when creating small figures. The lightness of the material and its pliability
and workability offers the artist the ability to work in fine detail to create
tiny features such as fingers. Wax is often worked using wire tools which can
be heated over a flame.
The finished product has a rough rugged vitality and shows the
marks of sculpting. This is a perfect material for creating small western
sculptures such as cowboys or Indians or animals. The lightness of
the wax does not require a heavy armature, which can be built with wire and
moved as necessary as the work progresses and the artist changes the
composition. An artist who works in heavy clay will often create a first draft
maquette from wax.
Water Clay: Water based clay is
essentially pottery clay and until recent years was the material of choice for
sculptors. One advantage of water clay is that its consistency can be
adjusted by the artist to fit the circumstances. As the sculpture is initially
modeled, the artist can keep spraying the clay with a water mist bottle to create a
smooth slick feel. I personally prefer this type of clay for portrait
busts. The wet surface of the clay allows the artist's hands to easily
glide over the form, feeling the composition. Between sessions, the work is
covered with a plastic bag to preserve moisture. As the work progresses
and detail is finally modeled into the sculpture, the clay can be allowed to
gradually dry with less and less moisture applied. A wet or dry paintbrush
becomes a valuable tool and can be used to blend detail and
surfaces.
Prior to making a mold, the artist can fire the
work and create a one of a kind permanent original. This process is tricky
and requires gradually allowing the sculpture to dry to a leathery state.
Then the artist must actually cut the work in half and hollow out the clay to a
thickness of about 1/4 of an inch. Finally the hollowed out work is
reassembled using a wet clay slush and allowed to dry very gradually over
several weeks. If the work is allow to dry too quickly or without being
hollowed out, it will simply crack and fall into hundreds of pieces. When the
19th Century French sculptor Auguste Rodin was called into the army, he wrote home daily
imploring his lady friend to keep wetting the burlap covering his unfinished
sculptures.
Finally the dried sculpture is fired in a pottery
kiln to create a durable terra-cotta original. While a fragile wet clay
sculpture would be destroyed in the mold making process, a fired terra-cotta sculpture
would be undamaged. A terra-cotta sculpture is most desirable if the artist is
not interested in a bronze casting or does not
need to create multiple copies from a mold.
The primary limitation is that the process
requires practice and finesse and if not done properly, the original can be
lost. Also during the process of drying and firing, the clay will
shrink almost 12% so if the artist is attempting to create a life size work, the
original must be pre-scaled up 12%. Another limitation is that water
based clay is that the weight of the water and clay can be massive and be very
difficult with which to work. With large figures with outstretched limbs, a
catastrophic collapse of the armature and work is possible. The best use
of water clay today is in busts and small figures which are destined for firing
into terra-cotta.
Oil Clay. Oil based clay presents
one of the greatest advances in sculpture technology in modern times. This
clay is much lighter than water based clay and can be purchased in a variety of consistencies
to suit the project. A sculpture modeled with this clay will not dry out
and will remain supple indefinitely. Fine detail is much more easily modeled in
oil clay and surfaces can be blended with a paintbrush containing lighter
fluid. Further, the clay can be temporarily rendered into the consistency
of soft butter by simply cooking it for a minute in a microwave (as long as it
is not your wife's microwave).
Limitations include the fact that the finished
sculpture is fragile and can be easily damaged. This requires that a mold
must be made to cast a permanent copy, destroying the original in the
process. However until the artist decides to cast the sculpture, it can be
carefully preserved in the clay state indefinitely with out fear of drying
out. Most artists recycle their oil clay using it over and over again
for each project. Oil clay is the material of choice when a sculpture is
created which is intended to be cast from a mold into multiple
copies.
Procedure to Model a Bust
( Sections, General to Specific, Tools )
Sections: After deciding on the important composition of a
bust, the artist will first model a rough featureless head and shoulders from
clay on a simple cross shaped armature. On that framework the sculpture will be
gradually modeled using the concept of
"sections." Since sculpture is three dimensional an accurate
three dimensional representation of the subject cannot be created by simply
considering one or two views; an unlimited number of sections must be
considered.
The easiest way to visualize the concept of sections is to
imagine a cut
through a clay bust with a long sharp knife from top to bottom dividing the
bust in half. The outside outline of the cut section will form a silhouette
which is called a section. It is this silhouette which the artist observes
when modeling and duplication the subject in clay. One section, however, is not enough;
there are an infinite number of sections that can be mentally cut (and observed), each revealing a
different silhouette. The artist then will literally turn his subject
around hundreds of times each time searching for new and revealing sections.
Sections need not be viewed vertically either. In portrait modeling, some
of the most useful sections are viewed from the top down or bottom up. It is not
uncommon to see an artist lying flat on his back on the floor looking up or
perching on a ladder straining to look down on a subject. By continuously
modeling the edge of many, many sections, the three dimensional form will accurately
and naturally develop. Of course this is an approximation of the actual process. In
practice the observation of sections blends subconsciously with the artist's
intimate
knowledge of the facial form and sensitivity to the subject. An
experienced artist can model for long periods after a brief view of the subject
retaining the forms of the face and sections in the memory.
General to Specific: Another equally
important concept in modeling sculpture is to begin with the general and end
with the detail. This may sound obvious, but it is the most critical skill
a sculptor must master. Each individual has a unique shape and
presence to his head and body, so that it is not unusual for one to recognize a
loved one from the rear without seeing features of the face. The artist
must resist the temptation to begin individual features too soon and concentrate
initially only on basic structure and the subtle form. In fact, a skillful
sculptor can create an excellent and readily recognizable bust which posses few
features. On the contrary perfectly formed individual features on a
misshapen head will be totally unrecognizable. Only after the artist is
absolutely sure the subject is captured in form, should features and detail be gradually
and carefully added.
Tools: Many people ask what kinds of tools
must be used to model sculpture. Despite the claims of tool manufactures, all
that is necessary is the artist's brain, eyes, and hands. An expensive and full
sculptor's tool chest will no more make one a better artist than the latest laptop
computer will make a better novelist. I know one very famous sculptor who uses
only a old kitchen spoon, fork, and butter knife. The best tool available
is the hand and thumb, and a bust can be 80% completed using nothing else.
The important thing to remember is that it is not the tools, but the
artist.
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