Flexible silicone or rubber material molded to replicate glass windows, bottles, and objects for safe stunt work – allows performers to break through or be struck by 'glass' without risk of cuts, complementing traditional sugar glass with durability and reusability in action sequences.
What is Rubber Glass?
Rubber Glass is a flexible silicone or rubber material molded into glass-like objects for safe stunt work. It allows performers to break through "glass" or be hit with it without the risk of injury from sharp edges.
Basic Principle
| Aspect | Description |
|---|---|
| Material | Silicone/Rubber |
| Purpose | Safe stunts |
| Property | Flexible, shatterproof |
| Appearance | Glass-like |
Material Types
| Type | Properties |
|---|---|
| Silicone | Transparent, flexible |
| Rubber | Durable, more opaque |
| Hybrid | Combined |
| Foam | For debris |
Applications
| Use | Description |
|---|---|
| Windows | Breaking through |
| Bottles | Impact props |
| Eyeglasses | Close proximity to face |
| Displays | Screen stunts |
Rubber Glass vs. Sugar Glass
| Aspect | Rubber Glass | Sugar Glass |
|---|---|---|
| Breakage Behavior | Bends, tears | Shatters |
| Reusable | Yes | No |
| Cost | Higher initial | Cheaper |
| Cutting Hazard | None | Minimal |
Manufacturing
| Step | Description |
|---|---|
| Mold | Create mold |
| Casting | Pour silicone |
| Curing | Harden |
| Finishing | Adjust appearance |
Optical Properties
| Property | Optimization |
|---|---|
| Transparency | Clear silicone |
| Reflection | Surface treatment |
| Thickness | Make realistic |
| Coloring | If needed |
Stunt Applications
| Scenario | Use |
|---|---|
| Window Crash | Body through window |
| Bottle Hit | Bottle impact |
| Car Crash | Windshield |
| Fights | Glass props |
Combination with Other Materials
| Material | Combination |
|---|---|
| Sugar Glass | For break detail |
| Candy Glass | Shard effect |
| Resin | Frames |
| Rubber Debris | Fragments |
Safety Advantages
| Advantage | Description |
|---|---|
| No Splinters | No sharp edges |
| Flexible | Absorbs impact |
| Predictable | Controlled behavior |
| Repeatable | Multiple takes |
Limitations
| Limitation | Description |
|---|---|
| Breakage Look | Less realistic |
| Splinters | No real ones |
| Sound | Different from glass |
| Light | Different reflection |
Sound Design
| Aspect | Solution |
|---|---|
| On-Set | Quieter than glass |
| Foley | Add glass sounds |
| Sync | In post |
| Layering | Multiple sounds |
Lighting
| Technique | Description |
|---|---|
| Angle | Control reflections |
| Diffusion | Soften appearance |
| Backlighting | Show transparency |
| Practicals | Credibility |
Cost Considerations
| Factor | Impact |
|---|---|
| Custom Mold | Initial costs |
| Reuse | Amortization |
| Quantity | Unit price decreases |
| Complexity | Design effort |
Best Practices
| Practice | Reason |
|---|---|
| Testing | Before shooting |
| Backup Props | For damage |
| Lighting Check | Test on camera |
| Sound Planning | Post-production |
Today
Rubber Glass is a technique for stunt coordinators that complements traditional Sugar Glass. The combination of both materials – Rubber Glass for safety, Sugar Glass for an authentic break look – enables convincing and safe glass-break sequences. VFX enhancement can add additional shards if needed.