Essential materials for props

Polymers used in stunts

Action films are always sensational, but although stunt men and women still manage to please us, much of that is due to the expandable materials they use. Leaping and falling in films are activities that require technique and special effects skills, but also good materials. Stunt men and women need protection in order to be able to keep getting back up after their falls. 
There is nothing better for this purpose than polymers. The back protectors used for dangerous physical stunts are made from a polypropylene layer for strength, while the shock-absorbing element is often made of expanded polyurethane for maximum comfort and safety. But these stunt artists do not only fall; sometimes they have to jump more than 10 metres high, which often requires a well-cushioned landing. These professional airbags are usually made from a film of stratified polymer material, most often in polyamide to provide the stunt artist with the safest possible landing.

From pasteboard to polymer plaster

Cardboard sets or studio filming, the Maciste era is now over. What has changed? The materials! Since the 1950s, film set construction techniques have evolved rapidly due to progress in the chemical industry. Set constructors use chipboard, plastics and new fast-drying paints. 
Since the 70s, materials like expanded polystyrene and thermoforming resins have permanently replaced the plasterboard sets of the historical epics. Sets are now often made from gypsum- and latex-based polymer plaster. This material allows sets and props to be created to look like stone, but are much more lightweight. It means that sets look much more realistic than in days gone by. On top of this,   they are fire- and water-resistant, and that means scenes can be shot outside of the studio, even when it’s raining!

A whole world of plastics

Rather than making some parts of sets life-sized, some directors prefer to build small-scale models. Such was the case with the Star Wars saga, in which most of the different planets were models made from polystyrene using an injection moulding process or from resin by thermoforming. 
They often include elements made from other materials such as rubber, used for certain tricky details and then reproduced in moulded plastic. For example, the planet Utapau, where the Jedi Order was said to have been founded, is in reality an enormous mock-up with a diameter of 10 meters. For filming purposes, it was cut in two to accommodate two teams of technicians working simulataneously.
The team also made thousands of litres of artificial lava using a natural polymer with a polysaccharide base, used in the preparation of milkshakes.

Spread throughout the mock-up, this mixture produced a flow of lava 1.30 meters wide. The actors, filmed against a green background, were later integrated into the film of the mock-up.

Plastics, monsters & co

Animatronics pioneer Carlo Rambaldi, The father of E.T., made his debut at Cinecitta Studios on pasteboard sets, to which he introduced plastic materials.
In 1957, fresh out of Ferrare, he saved the day for the director of White Knight, a B-movie inspired by the legend of Siegfried, by creating, in two weeks, a 14-metre mechanised wooden dragon covered in material and foam latex.
After numerous historical epics and other “Z” movies, his genius took him to Hollywood to create, in 1979, the horrific Alien of Ridley Scott, then the delightful E.T. of Spielberg, using metal frames covered with polyurethane skin.

In 1991, Rambaldi, like his American colleagues Rick Baker and Robin Bottin, the creator of the first Robocop in fibre glass and foam rubber, must have imagined that the fully digital Terminator 2 sang the swan song for his profession - until Spielberg decided, two years later, hesitating between animatronics and synthetic imaging, to combine the two approaches for the T-Rex in Jurassic Park.

Through a glass sharply

Bruce Willis, walking barefoot over broken glass to escape the clutches of the odious Gruber’s goons. Does that remind you of something? Die Hard, the film in which more glass gets broken than at a Cossack banquet. And what were the costs in terms of the destruction and injuries caused by these perilous scenes? Only that of the polyurethane resin used. No need for a miracle-worker to shoot these scenes; with some fake blood on his feet, Bruce does just fine! 
Designed to break on impact, this resin is essential for stunts and special effects and has become established as the perfect material for a wide range of objects destined to get smashed: fake windows, bottles, glasses, etc. Transparent or coloured, it is sometimes used in vast quantities on sets. First prize goes to 007, as entered in the Guinness Book of Records, for breaking, in the Ice Palace in Die Another Day, six and a half tonnes of polyurethane resin.

Undeadly weapons

With the new style of historical epics, swashbucklers or heroic fantasy, weapons experts and props designers have a wide range of opportunities to display their talents, in line with the unwritten rules of cinema warfare: realism, comfort and safety. Hence the frequent use of anachronistic materials.
In Gladiator, for example, Commodus and Maximus fight with a breast-plate covered in leather. But one is made of rubber and the other of foam latex. A number of originals were made and there were several versions - clean, muddy, blood-spattered. For Luc Besson’s Joan of Arc, winner of the César 2000 for best costume, the company Mediev´art, specialists in organic matrix composite materials, created a wide range of helmets and armour from fibreglass and metallised polyester resin.

Providing the armour for many Hollywood blockbusters, the New Zealand workshop Weta has made more than 15,000 bladed weapons. It was therefore able to provide each combatant in Narnia several models specifically adapted to suit his/her body shape. Swords, as heavy as the medieval weapons, made from forged steel, with engraved blades and pommels made from precious wood for those special scenes in which the actors must strike realistic poses. Less dangerous copies made from aluminium with urethane pommels were used to shoot several scenes as long shots without tiring the actors. Not to forget the swords, crossbows and assorted other weapons made from flexible urethane so that the stunt artists could let fly without risk.

Polymers - come rain or shine

It is not easy filming out of doors – except on those occasions when bad weather conditions fit in with the story line. So how can this problem be avoided? Put your money on polymers!

To recreate gloomy weather, a stormy sky or even a full-on hurricane, all you need is an aquarium. A little salt water, fresh water, add a latex mixture diluted with paint and Bob’s your uncle!
Because of the different densities, you get the different shades of cloud you were looking for. All that remains is to film them!

Along the same lines, it is no longer necessary to spend two hours shooting 35 takes in the cold near the Arctic Circle just to film one scene in the snow. Most of the snowflakes drifting across our screen are made from polyethylene. The effect is sometimes not very realistic, as in Edward Scissorhands!

That is why a super-absorbent polymer based process (SAP) is generally used, identical to those used in nappies. Osmotic pressure causes the grain of the polymers to swell and form a translucent gel that looks exactly like snow.

Resins pave the way to a fortune for spin-off products 

It is only a small step from film props and sets to figurines and other spin-off products. Georges Lucas understood this, and Star Wars toys have been a source of good income for him. 
The spaceships designed for the films were created in the Lucas Film modelling workshops. Most of them have a wooden frame covered with plastic sheets or composite panels (made from epoxy resin and fibre glass). Small pieces of plastic glued onto the shells of the vessels add essential details and give a touch of realism. 
Once the film has been completed, the spin-off business forms part of the promotion and increases the royalties from replicas and models. 
Star Wars characters also launched fashion for collectible figurines, both movable and static, made from PVC or polyester resin.

Light sabres and polymers

The history of the Star Wars light sabres overlaps that of polymers. The first light sabres were simple batons for which the luminous effect was created by rotoscoping. 
Nothing too remarkable there, except on the screen! In Return of the Jedi, the shining blades became carbon rods. And over the years, with progress and changes, the hilts were manufactured from resin and aluminium tubes before being replaced by carbon fibre specially developed for the film. 
These props were strengthened, because they frequently broke during combat scenes. But while the original light sabres were no more than plastic toys, it won’t be long before the real thing is on the market. 
Indeed, the US company Wicked Laser, specialist laser manufacturers, has produced a light sabre with a polycarbonate hilt and blade, just like those in Star Wars. Georges Lucas was a visionary. Thanks to plastics, his ideas have become reality!