It makes for a great movie stunt when the hero comes crashing through a window to save the day, or makes a death-defying leap out of a skyscraper. And it’s not just cool for you when you’re watching the movie, it’s fun for the actors and stunt doubles too! Movie stunts contain heaps of little details that make them more realistic so they really suck you into the action.

Stunt glass is one of our favourite movie props because it makes for a great piece of action, and it’s a really cool application of some simple ingredients and science!

smiling sand lizard

How Is Stunt Glass Made?

Stunt glass (sometimes also called Breakaway Glass), is a huge part of moviemaking. It’s not just used in action movies either – there are plenty of other TV shows and movies that have used breakaway glass to add dramatic moments to the script. In fact, stunt glass is super common, and it can be made into everything from simple window panes to glass bottles and just about anything else that’s going to shatter on screen.

The trick to making stunt glass into so many different objects lies in how it’s made. You see, traditional stunt glass is actually sugar!

turtles on log

Have you ever seen sugar lollies being made? Sugar and water get added to a pan and then cooked until what’s known as the “hard crack” stage. If you cook a sugar mixture to the hard crack stage, it becomes a hard lolly when it cools, like the kind you have to suck on instead of chew. When making stunt glass, huge batches of a sugar mixture are cooked up and then poured out into special moulds that shape the sugar into things like window panes or glass bottles.

When it cools, stunt glass ends up being clear and looking just like the real deal!

These days stunt glass is often also made from special resins (a type of plastic). These breakaway resins dry very brittle, so they shatter just like glass, except they’re safe for stunt actors to use when shooting movies.

What Are The Different Types of Stunt Glass?

Moviemaking has come a long way in the last 100 years, and so have all the techniques directors use to shoot realistic looking stunts. While stunt glass all used to be made from sugar and water, there are now two main types available:

  • Sugar glass. This is the traditional type of stunt glass we discussed above. By cooking a mixture of sugar, corn syrup and water to a temperature of 150°C, you can create a hard candy that cracks and breaks just like real glass. Sugar glass can be moulded into all sorts of shapes, but it needs to be used soon after it’s made. You see, sugar glass is hygroscopic, meaning it attracts water, so it softens and stops acting like glass if it isn’t used quickly.
turtles on log
  • Breakaway resin. It’s common now for stunt glass to be made from synthetic breakaway resins, which are a form of plastic. Breakaway resins are very brittle when solid, so they break just like real glass, except they’re super fragile and unlikely to hurt a trained stunt actor. As a bonus, glass made from breakaway resin stays brittle much longer, and it can even be used to hold liquids for a more dramatic effect!
turtles on log

Where Is Stunt Glass Used?

Stunt glass is probably one of the most used props on movie and TV sets. Whether they’re using breakaway resin or the older type of sugar glass, directors can buy or make stunt glass into just about any shape they want. Some of the most common shapes for stunt glass are:

  • Window panes
  • Glass surfaces like tables
  • Bottles
  • Jugs
  • Drinking glasses
  • Ceramic pots
  • Bowls and plates
  • Statues

Breakaway glass is super versatile. Colours and pigments can be added to the mix so that stunt directors can cook up everything from a clear window pane to a decorative ceramic vase! Stunt glass made from resin can also be painted, so it can be decorated to look like just about anything. And it doesn’t stop there, because the same technique can also be used to make bigger items that need to be broken on screen, like toilet bowls or sinks.

It’s important to say that stunt glass is used by trained stunt actors! While stunt glass made from resin or sugar is pretty safe, it can still hurt a person who isn’t trained to perform stunts.

Want to Learn More About Glass? Book Street Science’s National Science Week Show!

Are you interested in finding out more about how they make your favourite movies and TV shows? The National Science Week show being put on by Street Science dives into the chemistry and physics behind glass and delivers a shatteringly-good time! Students will love our Breaking Point show. Delivered by Street Science’s experienced team of teachers and instructors, we’ve got plenty of entertainment to keep students and their teachers engaged. If you’re interested in finding out more about the show or would like to book in your students, contact us today for the details!