Click for larger image
How the puppets are made...
The first part of the puppet to be sculpted is the head, which I tend to
sculpt from some sort of visual reference. Either a photo of someone in particular,
or a drawing. Even when working from a photo, I find it useful to do a drawing,
as it helps me to understand the features and structure of the face.
I sculpt the head in either plastaline or clay.
From this original, I make a mould, using silicone rubber encased in a
fibre glass or jesmonite shell. The shell provides the silicone with support
when the original is removed. I clean up the mould and then make a resin and
fibreglass cast.
Sculpting
An armature is needed to support the sculpted head. For plastaline I use a wooden ball fixed to of a piece of dowel, supported in a wooden base. (Click the image to see an animation of a head sculpt). The advantage of plastaline is that it doesn't dry out and shrink, this means that it is easier to work on something over a longer period. However it can be a bit more difficult to get a uniformly smooth finish.
Click for animated
head sculpt
If clay is being used then the armature cannot be solid, it needs to be something
with give. This is because the clay shrinks as it dries out and so compresses
whatever is inside it. To prevent the clay cracking around the armature you need
a soft core at the centre. I use wet sheets of newspaper folded into one long strip,
wrapped as tightly as possible around the end of a piece of dowel,
and secured with wire. You can then add small bits of clay and build up the head.
Whilst working with clay you must keep it as moist as possible, spray it with water
frequently and wrap it in plastic when you are not working on it.
Whatever material you sculpt in, the armature needs to be strong enough to support
the size of head you plan to sculpt. A relatively small head, 10cms from top
of head to bottom of chin, can end up using almost 2 lbs of plastaline.
For the eyes I use beads. It can be difficult to know exactly where to position
them, especially early on when there is little of the head to know where they should
be placed. I try to place them as accurately as possible by taking measurements from
the drawings. But often it is just trial and error. I have occasionally got quite
far with the sculpt only to realize that I need to move the eyes further forward or
back.
A finished clay sculpt can be sealed either by spaying it with a plasticised
aerosol paint, or by applying a layer of shellac varnish.
Moulding
The type of mould you make is determined by the material in which you are sculpting and the material in which you intend to cast the finished item. I usually cast the head and hands of the puppet in resin with fibre glass so the end result is a very rigid positive. This means the mould needs to flexible if it is going to come away from the details of the face and pull out from any undercuts without doing any damage, and remaining reusable. The best material for this is silicone rubber. It is very flexible and provides a highly detailed cast, picking up every mark and texture of the sculpted body part.
Photos of the mould
process
To make the mould I begin by building a clay wall around the head of the
puppet. By doing this you define the seam line where the mould will separate
and the two parts of the head will join together when you later cast the finished
head. I take the seam line over the top of the head along the edge
of the ear and down just along the bottom line of the jaw.
You can build registration marks into the mould by making small hollows or
protrusions in the wall. This means the two halves of the mould will line
up accurately should you want to join the head cast whilst it is in the mould.
(Because of the need to put fixings inside the head, I usually end up assembling
the head out of the mould. This can make it harder to match up the edges, as they
often distort fractionally when the cast is removed from the mould, making
it difficult to line up exactly.)
I then make the first silicone part of the mould. This is best done in two
stages. Firstly a thin layer of silicone brushed gently over all the features
and into the details of the face, and when this has cured, a thicker layer
6-7mm thick. This can be done in one go, but it is more difficult; in order
for the silicone not to slump, you need to add a thixotropic agent to the thicker
layer, which makes it harder to brush into the more detailed parts of the face,
around the eyes and the nostrils and ears, and increases the likelihood of air
bubbles.
The silicone on its own is not rigid enough to cast into, when removed from
the sculpt it will be soft and flexible. So the next stage is to make a rigid
case to support the silicone. For this I use resin and fibreglass, completely
encasing the silicone and brushing around the edge of the clay wall. (If the
clay is not too damp there shouldn't be any problem with the resin going hard.)
I build up three or four layers with a couple more around the edge of the
mould for extra strength.
When the resin has fully cured I remove all the clay from around the head
and clean up the back of the mould and head. Then I spray a wax based release
agent onto the exposed edge of silicone and repeat the process for the second
part of the mould. Before encasing the second half of the silicone mould in
resin and fibreglass I put a thin layer of vasaline around the fibreglass
edge where the two halves of the mould will meet. This will ensure the two
halves separate and do not just become one solid shell.
To seperate the mould I trim back the edge of the fibreglass to get rid of the
rough edge, to where it is a bit thicker. Then, using a thin tool or chisel,
I gently work around the mould to prise it apart. (When building up the fibreglass
shell for the mould I tend to make one or two areas around the edge a bit
thicker so there are some stronger points at which to lever open the mould.)
Finally I clean up the mould to prepare it for casting.
Casting
When the mould is finished the head is ready to be cast.
I use polyester (plastic) resin and fibre glass to make the puppet head. The
resin is a liquid and can be brushed or poured into the mould. It is mixed
with a small amount of catalyst which causes it to harden. I do not usually
pour resin, as a solid resin head is far too heavy to be of any use. Also,
on its own, resin has very little structural strength. To prevent it shattering,
it must be used with fibreglass. The resin impregnates the fibreglass and
the two materials create a very strong and reasonably lightweight structure.
I build up the head by brushing layers of resin and fibreglass into the mould.
The Head Mechanism
Many of the puppets that we use have a tilting head mechanism
(see drawing
at top of page)
which pivots the face upwards around a point where the head
meets the neck. This simple mechanism gives a huge degree of life to the
puppets thoughts and movements.
A piece of aluminium tube forms the neck of the puppet, at its top end a small
length of threaded rod pivots around a steel pin. The back end of this piece
of rod is fixed into the inside back of the puppets head. (Sometimes it goes
through a hole in the head and sticks out the back, to form a handle for the
puppet.) A wooden handle is drilled to take the bottom of the aluminium tube.
It has an elongated hole cut into its length through which a small trigger
connects to a short rod within the tube. Through the use of piano/steel wire,
the trigger rod pulls down the threaded rod at the top of the tube. It pulls
against a spring connecting the threaded rod to the tube, which returns the
head to its lowered (resting) position. When the head is in place on the puppet,
the aluminium tube travels down through a hole into the puppets body. The
shoulder construction of the puppet rests on the top of the handle (which
has a rounded top to it), so as well as controlling the head, the top of the
handle is supporting the body of the puppet.