I had the opportunity to watch a Masters student use foam latex in a mould they had made similar to the one I had created in the casting workshops. The only difference being is that this mould did not have a 'spigget' which is the hole that I used to bung; due to the nature of foam latex this is not needed in your cast.

I used a silicone based substance in my puppet head cast as it is a translucent substance and gives the effect of skin. Foam latex is used as an alternative to silicone when you need to keep the weight down on a puppet and would be well used on the body armature. It is the same as liquid latex but the kit that you buy turns this into foam.

You can buy foam latex from Mouldlife  which sells sillicones, latex and other materials that can be used in animation, film and theatre.

DO NOT DO THIS PROCESS ON YOUR OWN. Two pairs of hands are needed as the foam sets really quickly once mixed.

The foam latex comes with instructions on how to mix the foaming agent, curing agent (which sets it), and the gelling agent (which gives the bubbles a structure). However it is best to use half of the volumes stated as this mixes too much.

Make sure the puppets armature fits into the mould and it can close before you start to mix and substance together

1. Paint the release agent over the whole mould rather than just where the puppet will be. The foam latex will more than likely spill out over the whole mould when the two componants are joined together.
2. You will need a different speed mixer.Mix equal amounts of the latex with the foaming and curing agents for 30 seconds on a slow mix setting and then for 2 minutes, then 4 minutes on faster settings. The latex is thick and heavy so use a spatula to get the heavy material off the bottom of the bowl.
3. Finally add the gelling agent, the warmer the temperature is the faster the gelling agent works so
use less gelling agent than it states - it does not need that much and will set too fast. The bowl contents will be foaming and thickening, should be very smooth and very fine.

4. NOW MOVE VERY QUICKLY! The foam latex has already started to set. Paint a layer into the mould first so that it covers all the detail and fills all the more difficult to reach areas of the mould. Two people should be working on this, one on either side of the mould. Then pour the mixture into bothe sides of the mould.

5. Place the armature into one half of the mould and seel the two pieces together. Leave this to set.

6. Then you need to cook - if you don't cook it will set but it is not very durable or long lasting. Set the oven to 18 degrees. Make sure when you take your mould out of the oven that you don't let it cool too quickly otherwise it will crack and will be unusable.

I rescued this bit of foam latex from the dreggs of the bowl to get a feel of the material. It is a very spongey consistency and bounces back when gripped with your fingers:

I found this online tutorial which goes through the process step by step which is pretty handy:

The grand unveiling!!

Once opened, I could now remove all clay and plasticine from the mould along with the plasticine puppet head. The mould was then cleaned with water and a scouring brush to get rid of any unwanted dirt or left over clay.

I then peeled off all the plasticine from the puppet head that was cast to reveal the lightweight core and K and S; alternatively I could have made a new lightweight core but for time purposes this was the quickest option. I then needed to determine which way up the core sat in the mould so that the two pieces could close together perfectly and labelled this onto the sculpey.
A blob of plasticine was put over the tunnel in the back part of the mould ready for the silicone to be poured in. I painted a release agent into the mould and then placed the eyes into the right position. The mould is now ready.

The silicone substance we used to cast our puppet heads was Platsil and it can be bought HERE. It is more commonly used for prosthetics in TV and film but works well when casting puppets too. It comes as two components which when equal amounts are mixed together it starts to set. We also added some paint to colour it when mixing the gel, which you can see Katie and Mae doing in the picture above.

Acting quickly because the gel starts to set as soon as it's mixed, I painted a thin layer into my mould to ensure that the gel reached into all the nooks and crannies. As you can see from the picture area's like the nose, ears and around the eyes could be difficult for the gel to sit evenly by itself.

I then put the lightweight core into place which was made easier by the labelling being done previously and started dripping the gel around this into it started to overflow into the shim. I did this to both sides of my cast.

The original plasticine model had been created before the workshop; I then had to remake this model that included a lightweight core and K and S technology.
    A lightweight core is not only sensible in terms of making the puppet lighter but it is brings the cost of materials down as well. This should sit where the back of the skull would be on your puppet with the facial features protruding off of this. Using a piece of pre-cooked lightweight sculpey that is set around a long piece of K and S, I moulded my character again, this time using a harder plasticine (sculpting grade) which meant that it would be harder to disfigure during the process of making the mould.
    I had to change some of my characters physical features due to the fact that in the original figure I had used spherical buttons for the eyes whereas for the workshop I was given the smaller beads with a pin hole more commonly used in stop-motion puppets. I had to make sure there was a length of K and S either side of the characters head as this acts as a brace holding the armature inside of the mould.

Using Potters clay rolled into balls and built into layers in this case onto a bit of foam board, I made a 'bed' for my puppets head which would be cradled in the centre. The half way line around the puppets head needed to be identified. This is half way up the K and S when the puppet is lying horizontally and facing upwards, this line is followed around the puppets head. This is the point that the clay is built up to.

The bed then needed to be smoothed with no gaps around the object so that no plaster can filter through when it is poured into the mould. The bed needs to sit at an even level with the half way line, the first image shows the uneven surface when the balls were first smoothed flat, this had to be corrected so that it looked like the last image. I achieved this by using a small unused rubber with a right angle which enabled me to smooth the clay around the head as well. After this I fettled the whole area with a damp sponge, this also helped to get rid of any excess clay from the plasticine head.

The clay bed then needed to be cut into a circle using a clay knife. The best way to get a circular shape is to keep the knife still so that it stays at an upright angle and rotate the board with your other hand. In the second picture, the gaps that are visible at the bottom of the clay bed are where the balls haven't been blended together and it is necessary to leave it this way for a later stage in the process.

I then cut a chunk out of the bed in a triangular shape. This would give the plaster a catch so that when using the mould I would know where to align the two pieces easily and the cast would be in perfect alignment of its two sections.

A biting edge or a shim is a channel in the bed around the object. This is created by laying a thin rolled strip of clay around the object with the catch between this and the edge. If you didn't have a lot of space between your object and the edge of the bed, your shim would best fit as shown in the image on the left. If you had room between your object and the edge of the bed then it is best for it to lie as it does in the image on the right.

I then dug out the clay shim that remained leaving just the plaster mould and the plasticine head. I could then clean the plaster surface with water and a sponge and scrubbed away any rough bits of plaster with a green wire scrubby cloth. The shim was then replaced with fresh clay and a triangular wedge of clay was placed on the edge of the plaster which would enable me to prize apart the two bits of plaster when the second layer had set.