Life casting Materials: Alginate & Silicone.

To be able to create accurate prosthetic pieces that an actor would have applied to them to portray a character or to look older, they must have their face cast to create a lifelike ‘mask’ to work on, this process is called ‘life casting’. Sculpting on a face cast will ensure the prosthetic fits perfectly to the model because it captures all of the models features and contours. To do a face cast the model has a special prosthetic grade cream known as alginate, which is derived from seaweed, or a special grade of silicone that can be used to cast the face and other body parts applied.

Once the alginate is mixed with water it becomes a paste like substance that is applied directly to the models face (or body). The consistency of the paste is determined by how much water is added to the mixture whilst the temperature of the water used will effect how quickly the alginate solidifies. When dried it forms a negative piece which can be filled with certain materials, most commonly plaster, to create the positive to which the prosthetics can then be sculpted on.

Before alginate was used there was only one flexible impression product and that was ‘moulage’. A reversible material that had to be heated up and then brushed on to the model whilst still hot. The material didn’t have much tensile strength so a heavy coating was always required, along with a mother mould of plaster to hold the shape. It could be reused multiple times as long as the water content was kept to the correct level but it was still a tricky material to use and required a lot of preparation and after care.

Once alginate came along moulage was out of the picture because of how easy alginate was to prepare and apply and how it could form a much stronger mould. The setting time of alginate can range from 3 minutes up to 9 minutes or more if a retarder is added. Alginate still requires a plaster mother mould however and the mould needs to be filled with the positive making material as soon as possible as the alginate has a tendency to shrink if left out in the open for too long.

Separators can be applied to ensure that two materials can be easily withdrawn from each other. An accurately selected sealer-separator combination stops the moisture from the material from penetrating into the pores of the mould or hair on the body. It also allows free movement. The basic requirements of a satisfactory separation medium are that it:

1. Prevents adhesion of the cast;
2. Protects and lubricates the surface of the mould;
3. Spreads easily and uniformly in a thin, continuous insoluble film;
4. Will not react destructively with the gypsum surface or with the mould surface.

Petroleum jelly (vaseline) is one of the most well known separators in general use. It is used to separate any gypsum material from any other during the casting process. It can also be used to coat hair when a face cast is taken.

Sealers can be applied to plaster or stone face casts with shellac which protects them from the oils in the clay that are used for sculpting and to make separation easier.

Face casting can be a messy process so it is best to have a separate area away from the main make-up area for carrying out the procedure. Some of the materials can also be harmful if breathed in so adequate ventilation is required.

Requirements of work area:

• Comfortable chair with back support and easy-to-clean surface.
• Low-level storage for bulky materials.
• Washable floor.
• Sink area.
• Effective lighting.
• Strong, washable worktop.
• Adequate ventilation.
• Waste disposal facilities.

It is important to ensure that all the materials required for the face casting process are prepared and set out in a logical way. The model must never be left alone during the face casting session so materials must be close to hand. The more prepared you are the more smoother and effectively the casting process will run.

The model must feel comfortable before being face casted as if they panic the entire process will have to be started again from the beginning. Having a good manner towards the model and making it seem that you are in control and confident of your own abilities will all instal confidence in the model. It is a good idea to talk through the entire process with the model to give them a better understanding of what will be happening which should help to keep them calm during the whole process. Most models will have similar concerns though such as feeling trapped, having difficulty breathing, feeling panicked and claustrophobic.

Communication throughout the face casting session is key. Informing the model will calm them but communicating with them the entire time will also help and of course they are unable to talk for the majority of it so hand signals are needed – a thumbs up for ‘okay’ or ‘yes’, a thumb down for ‘no’ and tapping the legs or any other signal for a ‘get this off of me quickly’ situation.

The materials needed other than the alginate are:

• Protective clothing for the model
• Protective materials for the model’s hair – bald cap/clingfilm
• Vaseline
• Cups for water/cups for alginate
• Scissors
• Plaster bandage (modroc)
• Mixing bowls – 1x alginate, 1x plaster bandage
• Scrim/net
• Low expansion plaster

The plaster bandage is needed to provide support so the alginate mould retains its shape. It is a good idea to use warm water when dipping the bandage as this will decrease the setting time of the plaster making the process go quicker.

Scrim/net is usually made of cotton or flax and is used to add strength and reinforce the mould to prevent cracks. It is applied as a square.

All plaster expands but low expansion plaster expands less and is less likely to crack. The plaster is poured in to the negative to create the positive.

The majority of materials required for the face cast session can be prepared before the model arrives. A range of sizes of plaster bandage will be needed to cover the forehead, eyes, neck, chin, with smaller pieces being used to cover the nose and around the nostrils.

– Debreceni, T. Special Makeup Effects FOR STAGE AND SCREEN.

The prepared working area with strips of modroc for the plaster mother mould. Very neat, very clean.

The model needs all the hair on their face (eyelashes, eyebrows, beards and moustaches) to be lubricated to protect it from the alginate, with hair on the head protected by clingfilm or a bald cap. The model should be told to try and keep a straight, neutral, face at all times.

Face and neck lifecasts are the most common for when it comes to creating a new character with prosthetic application as other effects on the body can be achieved by using flat pieces (the majority of the time). The way an artist will life cast a model will change depending on the artist, Debreceni in ‘Special Makeup Effects for Stage and Screen’ claims that if you were to poll 50 artists about the way they do a life cast, you are likely to get 25 different methods or more, saying that he himself has changed his methods several times and will probably continue to do so as the materials change and advance. This however makes me ask myself how can there be so many different ways of applying alginate to the face, it must come down to the little details such as where the artists applies the first bit of alginate or something along those lines, I know that one of the teaching technicians – Wayne Humphrey mentioned that when he takes a cast of the face he applies the alginate over the nose and gets the model to do a sharp blow from their nose to create the air holes and then goes on to cast the remaining areas of the face.

Creating The Negative.

The most important part of taking the face cast is to constantly make sure that the model is okay and to keep talking to them to keep them settled as well as making sure the nostril area remains clear of materials.

The room, water and model’s body temperature are all factors that effect the speed at which the artist works.

• The plaster bandage is cut in to different size strips. At a ratio of 1 part water to 0.5 part alginate, each material can be placed in to plastic cups. The alginate can be placed in to a mixing bowl and the water can be added when everything else has been appropriately prepared.
• The model’s clothing is protected by placing large plastic bags (bin bags) over the upper and lower part of the model, the hair is also placed under clingfilm or bald cap making sure to cover the ears.
• The hairline is drawn on to the clingfilm/bald cap and transfer on to the alginate once the face is cast showing the artist the model’s hairline.

– Debreceni, T. Special Makeup Effects FOR STAGE AND SCREEN.

• All facial hair then has vaseline applied, and depending on how far back the artist wishes the cast to go the clingfilm/bald cap is also lubricated to stop the alginate from sticking to it.
• If not already done so, the process should be explained to the model so there are no surprises during the cast.
• If the character that is going to be created will be wearing dentures/false teeth then the model should wear them during the cast to get an accurate cast.
• If the model is sitting with a straight back then the water can be gradually added to the alginate and mixed together quickly.

– Make-up Designory (Company) and Thompson, P. Make-up Designory’s character make-up.

• The alginate paste is applied quickly and accurately to the face starting at the top of the models head and then spread evenly around the rest of the face making sure to keep the nostrils open and clear so the model can breathe. The alginate should be about 1/2 inch in thickness and even around all the face.

– Debreceni, T. Special Makeup Effects FOR STAGE AND SCREEN.

– Debreceni, T. Special Makeup Effects FOR STAGE AND SCREEN.

• Certain areas require the alginate to be pushed into them with a slight amount of pressure then when applying to the rest of the face, these areas are the corners of the eyes, the eyelids, the corners of the mouth and under the lower lip, this reduces the chance of any air bubbles.

– Make-up Designory (Company) and Thompson, P. Make-up Designory’s character make-up.

• The jaw and chin area can also be an area where air bubbles can form so care needs to be taken when applying the alginate in these areas.
• The alginate is spread as far down the neck as needed.
• As the alginate will naturally slowly run down the face under its own weight, it should be lifted back up the face from time to time.
• The nose is often the last area to have alginate applied but it is another area where air bubbles can occur so be sure to apply a slight bit of pressure when pressing the alginate in to the crevices around the nostrils.
• It is a good idea to have someone ready to prepare another batch of alginate just incase you run out but it must be applied quickly as alginate will not bond to dried/set alginate.
• Now is the time to apply the net or scrim if you wish to to add some strength to the cast.
• The plaster bandage strips are applied to produce a mother mould to secure the alginate. Starting from the outside and working inwards, the strips are folded in half to create a two-ply strip, run though warm water (the warm water decreases the amount of time it takes to set, adding salt to the water can reduce the time even more) to wet it, rinsed out slightly and then placed on to the cast.

– Make-up Designory (Company) and Thompson, P. Make-up Designory’s character make-up.

• The plaster bandage should be around four layers (four-ply) in thickness and smooth all round.

– Debreceni, T. Special Makeup Effects FOR STAGE AND SCREEN.

• Smaller strips of plaster bandage should be used around the nose area being careful to keep the nostrils unobstructed.

– Make-up Designory (Company) and Thompson, P. Make-up Designory’s character make-up.

• Longer strips of plaster bandage that are folded up a rope-like shape can be placed all the way around the outside of the cast to add more strength.
• Once the plaster has hardened and is beginning to cool it can be removed from the model. The model should puff their checks and wiggle their face whilst leaning forward slightly to break any suction between the skin and alginate. The artist should always have control of the cast though to stop it from slipping or falling, becoming damaged.

– Debreceni, T. Special Makeup Effects FOR STAGE AND SCREEN.

• If the cast is sticking in places the artist can run a finger between the alginate and skin to help loosen it but making sure to be careful around areas with hair.

– Make-up Designory (Company) and Thompson, P. Make-up Designory’s character make-up.

• Once the cast has been removed the model should be told to keep their eyes closed as the sudden change in light can be uncomfortable for the model.

– Debreceni, T. Special Makeup Effects FOR STAGE AND SCREEN.

• The creation of the negative is now complete, it should be inspected for air bubbles and impurities. Some minor bubbles are fine and can be easily cleaned up once the positive has been cast but any large or serious imperfections may mean the entire process needs to be repeated.
• The nose holes are ‘plugged’ with a little bit of alginate and plaster bandage is placed over the alginate just as before.
• The cast is now ready to be filled with the material of choice to create the positive.
• If more then one person was working on the life cast then the extra person can clean up the model whilst the artist prepares to fill the negative.

An alternative to using alginate to take the face cast is using silicone. This method has been around for a while but is not very popular with professional make-up artists because of the additional cost of materials. The benefits of using silicone instead of alginate to cast the face is that it is lighter so it drags the contours of the face less (especially evident when casting mature skin). When silicone is applied it is not as cold as alginate so there is a much smaller chance of ‘goose pimples’ appearing on the cast. A silicone mould can also be used multiple times as it will not shrink or distort.

The preparation for using silicone is much the same as alginate but lubrication needs to be applied to the entirety of the models face and particular care taken with hairy and delicate areas.

Creating The Positive.

The positive should be made as soon as possible from when the cast is removed from the model as the alginate will begin to dry and can become misshapen, if it is not possible for the positive to be cast straight away then wet paper towels can be placed in the cast surrounding the alginate and then sealed in a bag, this is only a temporary solution though.

• The cast should be placed face down in a bowl or a box, supported with clay underneath if needed to keep it level and to stop the nose from touching the surface.
• Add low expansion plaster to a bowl of warm water making sure there are no lumps and mix to create a smooth paste.
• An optional detail layer of plaster can be applied carefully to the cast before pouring in the plaster but it is not essential for when casting just the face.
• The plaster paste is poured into the mould and filled to the edges of the alginate making sure not to overfill the mould. It is then left to set.
• Once the plaster is set the plaster bandage and alginate can be removed.
• Any imperfections can be removed/repaired at this stage.

The graph below is taken from Make-up artistry : for professional qualifications. Conway, J.

Creating a full head cast takes the life cast one step further. It includes casting the back of the head as well as the front, and comes down to below the collar bone area all the way around the back of the model.

Clingfilm can be used to protect the hair but it is generally easier to just apply a bald cap to the model. It is important that the bald cap is secured all the way around and the hair under the cap is as flat to the head as possible. Any hair outside of the cap needs to be appropriately lubricated.

Instead of casting the front of the face first this time the back of the head is cast first which means that the model will spend less time with alginate and plaster bandage over there face creating a claustrophobic situation. Debreceni book and Kehoe book both advise the artist to use alginate on the back of the head but surely this is not necessary as there is no detail to capture, the only way I can see this being beneficial is when it comes to rafting the plaster cast but that doesn’t take too long. Both books do encourage casting the ears as part of the entire cast however, is this the reason for using alginate on the back part so you can get the ear?

If alginate was used on the back of the head it would have the plaster bandage placed on it to create part of the mother mould, any excess alginate is then cut away. If no alginate is used on the back then the plaster bandage can be applied directly to the back of the model as long as the entire area is lubricated.

The edge of the back mother mould is lubricated other wise when the front part is done the two parts would lock together. Once the edge of the plaster bandage is fully lubricated the front can have the alginate applied in the same way as when doing a face cast, the only different being that this time the alginate needs to go further down the neck to be in line with the back mould. Plaster bandage is applied over the alginate creating the second part of the mother mould. It is important not to go too far over the back section of plaster, 1cm or 2cm in depth is fine as long as it doesn’t go past the lubricated area.

Once the plaster bandage is set and cool, marks can be made using a marker pen along the seam which will help when putting both mould parts back together it can then be removed in the same way as would be done with a face cast. There may be slightly more resistance and it could also be harder for the model to lean forward but it will eventually come loose.

– Debreceni, T. Special Makeup Effects FOR STAGE AND SCREEN.

Once both the back and front piece of the mould are free, the nose is filled and plaster bandage applied (just like with a face cast). The two mould pieces are then put back together and can be secured with duct tape or plaster bandage to make it even more secure. The entire mould is then placed in to a large bucket or sturdy box with padding to keep it in place.

– Debreceni, T. Special Makeup Effects FOR STAGE AND SCREEN.

– Debreceni, T. Special Makeup Effects FOR STAGE AND SCREEN.

A large batch of low expansion plaster is mixed and is slowly poured in to the mould bit by bit. After each pour the artist should reach inside the mould and work their way around the inside in an attempt to remove any air bubbles as well as attempting to achieve the greatest possible amount of detail. This is repeated until around the chin area when the remaining plaster can be slowly poured in to the mould to the top. The mould is then left to completely set which will take many hours.

Once fully set the plaster bandage and alginate can be removed to reveal the completed head cast, any impurities can be rasped down. That is essentially the completed process of a head cast although more work is needed for the cast to become ready to be sculpted on.

– Debreceni, T. Special Makeup Effects FOR STAGE AND SCREEN.

Silicone for life casting is applied in the same way. A and B (or alginate and water) are mixed together thoroughly and then applied to the model. The silicone mix is slightly thicker then alginate and warmer. Where as an alginate cast can only have a positive taken from it once, a silicone cast can be used for multiple pulls for years to come and it also wont shrink. So if you needed to take multiple casts from the life cast you would want to use silicone other wise you would have to take an alginate cast from the plaster cast that was cast in the original alginate life cast.

Silicone life casts can also be useful if there is a chance of working with the actor or model again as it saves having to do another cast. It is a more expensive material however, possibly too expensive at the moment considering how cheap alginate is.

SOURCES:

Baygan, L. (1982) Techniques of three-dimensional make-up. Watson-Guptill.

Conway, J. (2004) Make-up artistry : for professional qualifications. Oxford: Heinemann.

Debreceni, T. (2009). Special Makeup Effects FOR STAGE AND SCREEN. 2nd ed. Massachusetts: Elsevier.

Delamar, P. (2003) The complete make-up artist : working in film, fashion, television and theatre. 2nd edn. London: Thomson.

Kehoe, V.J.J. (1991) Special make-up effects. Boston, MA.: Focal.

Make-up Designory (Company) and Thompson, P. (2005) Make-up Designory’s character make-up. Burbank, CA: Make-up Designory.

Musgrove, J. (2003) Make-up, hair and costume for film and television. Oxford: Focal. (Media manual; Media manuals.).