Hi there! Welcome back to my blog.
This week we are going to be focusing on life casting: What is it? Why do we do it? How do we do it?
First of all, lets talk about what life casting actually is and why it is done in industry. Life casting is taking a three dimensional copy of a living human body, through the use of moulding and casting techniques. The face is the most common body part to be casted in prosthetics. This is the first stage in creating any prosthetics for film and television as it allows for prosthetic pieces to be made that will perfectly fit the model they were designed for. The process is safe and simple, as long as the makeup artist is professional and performs safe practise throughout (Conway, 2004).
Making a Face Cast
To make a face cast, a bald cap should be applied first (Figure 1). This is because the alginate may get stuck in the model's hair if only doing a half face cast, but if a full head cast was being done then a bald cap would be applied to get the shape of the model's head. The bald cap must not be wrinkled, but not pulled so tight that is distorts the model's features.
Figure 1: Video of Applying Latex Bald Cap (O'Connor, 2021).
Vaseline should be applied to the bald cap because it will stick to the alginate. Vaseline should be applied to eyelashes and eyebrows so they don't get pulled out (Huaixiang ,2012). The hair line, jawline, around the ears and eyebrows should all be marked using aqua paints as they will transfer to the alginate and then will transfer to the plaster. These markings are extremely important, otherwise, there will be
no indication where these features are and you Figure 2: Video of Applying Vaseline and Aqua Paint (O'Connor, 2021)
won't know how far to take the sculpt - see Figure 2.
Figure 3: Video of Applying Alginate and Mod Rock (O'Connor, 2021).
Figure 3 shows the process of applying the alginate and mod rock. Alginate is spread over the model's face, it is a powder that gets mixed with water to create a paste, which then sets into a flexible material (Conway, 2004). Figure 4 shows how Smooth-On use a life casting silicone called 'Body Double'.
Life casting silicone is much thicker than alginate, so holds its shape better. It is more durable than alginate and can be used more, however it is much more expensive and both do a good job. Alginate was used over life casting silicone because it is much more cost efficient.
Figure 4: Body Casting (Smooth-On, 2020). Being the first time a face cast was done, the mixture was made with cold water as this allowed for more time before it set. The alginate was applied everywhere apart from the nostrils and there was lots of communication with the model to ensure they were comfortable throughout the whole process. Mod rock, or plaster bandages, were then applied to reinforce the structure, since alginate is so flexible. This was left to set, with continuous checks with the model that she was okay and comfortable.
Figure 5 shows that spatulas were used to gently pry the cast away from the model's face. The model moved her head forward, which helped with the removal of the cast because it allowed the cast to come away from the face easily because gravity was pulling the heavy cast down. The model was asked to wriggle her face as this allowed for the cast to come away from her face
Figure 5: Video of Taking Face Cast Off (O'Connor,
Figure 6 shows how the aqua paint has left markings on the alginate, which is exactly what is needed as this will transfer on to the plaster mould.
The nostril holes should then get filled in with plaster and when dry the cast then gets filled with plaster. This should be done almost immediately after being taken off to avoid the alginate doesn't shrink.
A little amount of plaster should be poured in to begin with and then dragged up the sides and rubbed into all the crevices to ensure it is picking up all of the detail. Then the plaster can get poured into the cast. Scrim can be added, seen in Figure 7, which helps to fill out the plaster face cast and keep it lightweight.
Figure 8 shows the plaster face cast that was created. All the facial details have been picked up well. The model must have had her mouth slightly open because the alginate has slightly entered the mouth, meaning there is a cast of her front teeth. The aqua paint has marked the cast well, which means that the next stage can be completed successfully: drilling in holes on the cast where the eyebrows and hairline are. This is drilled in the cast because the plaster will be washed and sanded to get rid of any unwanted textures that may have been created by the bald cap edge, for example, so the aqua paint is likely to wash off.
Making an Arm Cast
is a very similar process to making a face cast, however, the alginate is just put straight onto the arm and hand. Figure 9 shows the process of making an arm cast.
Figure 9: Video of Making Arm Cast (O'Connor, 2021).
The alginate should be made with slightly warm water to ensure it is thicker and to stop it from being so runny and running off of the arm. This is put however far up the arm that is desired. This is left to set, and then mod rock is applied to reinforce the structure. This can then be pulled away from the board when set (Figure 10). Then the end of the cast where there is a gap should be secured with mod rock (Figure 11). This cast is then ready to be filled with plaster, moulded and taken out (Figure 12). The plaster should be left to set and be taken out in the same day otherwise there is a bigger risk of fingers snapping.
Making Ear Casts
is a lot different to casting the face and arms.
Figures 13, 14, 15, 16, 17 & 18: Making Ear Cast (O'Connor, 2021).
Figures 13 - 18 shows the process of creating the ear cast. Two cups were cut in half and cut and taped back together. This was to make sure that they were the same circumference all the way around so that when it came to it, the mould would easily come out. Plastic wrap was used to protect the model's hair and surrounding areas because alginate would have stuck to this and been difficult to get out. Cotton balls with vaseline was used to plug the model's ears in order to stop the alginate leaking in the ear (Huaixiang, 2012). The alginate was then poured in and was let to set. Once it had set, it was gently pulled up from the ear, being careful not to tear or rip any of the alginate. The gaps between the cup and the alginate was filled in with clay, because the polyurethane resin would have leaked through the gap. The resin was mixed and poured in and left to set (more on polyurethane resin to come in the snap mould blog). Once it was set, the cups were cut away, and the ear moulds were ready to be cleaned and rasped and then were ready for sculpting.
Thank you for reading this week's blog! Next week we will be correcting the core ready for the fibreglass jacket.
See you soon!
Alysha:)
Reference List:
Body Casting: How to Mold a Female Torso Using Body Double Silicone (2020) YouTube video, added by Smooth-On [Online]. Available at https://www.youtube.com/watch?v=mc2YQ1pI12w&t=1s (Accessed 13 October 2021).
Conway, J. (2004) Make-up Artistry, Oxford, Heinemann Educational Publishers.
Huaixiang, T. (2012) Costume Craftwork on a Budget, Oxford, Focal Press.
O'Connor, A. (2021) Arm Cast [Image]. York.
O'Connor, A. (2021) Arm Cast Blocked Up [Image]. York.
O'Connor, A. (2021) Arm Cast Taken Off [Image]. York.
O'Connor, A. (2021) Face Cast Off [Image]. York.
O'Connor, A. (2021) Making Ear Cast [Images]. York.
O'Connor, A. (2021) Plaster and Scrim [Image]. York.
O'Connor, A. (2021) Plaster Face Cast [Image]. York.
O'Connor, A. (2021) Video of Applying Alginate and Mod Rock [Video]. York.
O'Connor, A. (2021) Video of Applying Latex Bald Cap [Video]. York.
O'Connor, A. (2021) Video of Applying Vaseline and Aqua Paint [Video]. York.
O'Connor, A. (2021) Video of Making Arm Cast [Video]. York.
O'Connor, A. (2021) Video of Taking Face Cast Off [Video]. York.
Comentarios