Ron Graham
Puppets and other papier mache creations.
Fine art with paper as medium or support.

Fact Sheet 2
Casting puppet parts in paper pulp

Introduction

Here we discuss a three-step method of puppet making, rather than modelling a puppet directly in papier mache. The three steps are...

• 1. Make a model of a given part in any suitable material,
• 2. Make a mould in silicon from the model,
• 3. Take a cast in paper pulp from the mould whenever you want to include the part in a puppet.

There are clear advantages to this method...

• Saves you work and time. You can reproduce a part many times in cast papier mache, having modelled it only once. It might take you hours to make the model, but then only minutes to reproduce it.
• Permits a choice of modelling materials. The model will be cast in paper pulp which is light in weight, easily joined, durable, and able to be painted. These characteristics are essential on the puppet. The model, however, need have none of those characteristics.
• Inexpensive. A modelling material may be costly, however a model is a one-off expense spread over the production run of paper replicas.
• Better finish. Puppets made directly from papier mache usually look pretty rough because it is impractical to laboriously reshape, fill, and smooth each individual puppet. A paper pulp cast, however, will reproduce the surface of the model. A puppet made up of cast parts will therefore reflect the workmanship of the model maker.

Modelling materials and methods

Models can be made of almost any material with but one consideration. Will the model store so you can make further moulds from it? Some suggestions for modelling materials are...

• Paper mache. Mix paper pulp, glue, linseed oil, and whiting. Build model bit by bit, drying thoroughly at each stage. Coat dry surfaces with white glue before adding more pulp. Carve, rasp, file, saw, fill, sand, and burnish the dry object.
• Wood. If you like carving wood, go for it. The paper casts will reflect the character of the wood carvings and puppets made from them will look as though they are carved from wood.
• Hard soap. Carves and smooths well.
• Plasticene. Soften by a few seconds in microwave oven. Leave model in fridge overnight to harden. Store models in lidded plastic containers.
• Clay. Fire clay models in a kiln. Alternatively, buy a clay-like modelling compound that dries hard in the air or in an oven.
• Found objects. You may discover something in nature or in a junk shop that you can incorporate into a model.
• Combinations. A model may combine two or more materials

Note: Make a model about ten percent larger than the object should be. This allows for shrinkage of the paper cast. Also, contrive your model so that the silicon mould will have a well defined rim at its opening.

Making moulds simply and safely with silicone

Using a scrap of cloth, coat the model sparingly with petroleum jelly/vaseline. Remove excess from crevices with a brush. Vaseline is a releasing agent preventing the silicone from adhering to the model. Now cover the model with silicone using a flat stick. Keep the coating to about 3mm and avoid air bubbles. After 24 hours add a second 3mm coat. After a further 24 hours remove the model. The flexible mould is now ready to use.

Note: Use the clear silicone specified for glazing. Make sure it is acetic cure. This exhudes strong vinegar while curing, but is safer than the chemicals in other types. Hardware stores sell silicone in 300ml tubes which fit a convenient plunger gun.

Casting considerations: compaction, evaporation, and release

Papier mache is pressed into the silicone mould to form a layer about 3mm thick all over the mould’s interior. In warm air or sunshine the paper cast will dry within 24 hours.

There are three major considerations that you must address, from the time you start making your model right through to the time you pull out your paper cast...

• Compaction. Pulp must be firmly pressed on to the mould surface. This encourages the pulp to faithfully reproduce surface detail, and encourages the cellulose fibres to interlock, strengthening the cast. To aid pulp compaction, lay a fragment of denim or felt between your fingers and the pulp surface as you press.
• Evaporation. The mould must have a wide opening so that the layer of paper pulp is exposed to the air. Convolutions in the mould must not create a mass of pulp or a dead air pocket in any place. Air must freely circulate over the entire pulp layer, everywhere within the mould. Contrive your models so that the mould will be as much as possible like a bowl. This requirement is not as restrictive as it sounds. It just requires thought and forward planning right from the model making stage.
• Release. No releasing agent is necessary on the mould. As the cast dries and shrinks, it releases cleanly from the silicon mould. Another aspect of release is undercut. A mould has undercut when two points on its interior can be connected by a line extended in direction that the cast will be drawn out. Undercut in rigid moulds locks a cast in and it cannot be drawn out. However the flexibility of silicon moulds, along with shrinkage in the cast, provides some tolerance for undercut.

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