Adhesion Matters - Adhesives for Filmmaking

Episode Date: August 5, 2025

In this popular series about adhesives, we discuss these often-overlooked, yet absolutely critical, components that enable cinematic illusion in Hollywood. From ancient organic glues to modern synthetic polymers, these materials have evolved to meet the increasing demands of filmmaking, facilitating everything from intricate special effects makeup to robust set construction and detailed prop fabrication. The development of adhesives has been driven by a continuous need for greater stability, durability, versatility, and efficiency, often spurred by broader industrial advancements. Despite the rise of digital effects, the tactile, tangible elements of cinema continue to rely heavily on advanced adhesive technologies, highlighting a crucial synergistic relationship between materials science and cinematic art.

Welcome to the Deep Dive. We're plunging into the hidden layers of, well, some pretty fascinating topics. Bringing you insights you probably didn't know you needed. Exactly. So have you ever wondered, like, how a zombie's gruesome face stays put during a chase scene? Or how a spaceship model holds together after getting blasted. Right. The unsung hero, the silent architect behind all that movie magic is something you probably don't even think about.

It heases. Glue. Mm-hmm. Today we're doing a deep dive into the world of glues in Hollywood. We'll cover everything from the very start of cinema right up to, you know, modern blockbusters. And our mission, if you will. Our mission is to uncover how these seemingly mundane materials are actually indispensable. They enable pretty much everything you see on screen.

Sometimes they even drive the plot. It really is incredible. The synergy between material science and filmmaking, it's always been there, like hand and glove. This whole unseen craft of adhesives. It's basically the backbone of cinematic illusion. It makes things feel real, holds effects together, literally. Okay, let's unpack that, starting right at the beginning. Humans have used adheses for, what, millennia, long before we really understood the chemistry.

Oh, absolutely. We're talking basic, organic glues. Like records show tree sap being used way back, 4,000 BC, for fixing pottery. Right, and by 2000 BC, there were actual written instructions for making fish glue. Imagine that. Wow. And the ancient Egyptians, around 1,000 to 1,000 BC, they were masters at woodworking, murals, using animal-derived glues. You can even see it in their stone carvings.

It just shows how universal this need was. Egyptians, Romans, Chinese, they all figured out how to stick things together using biological stuff. It established a sort of technological baseline. But what were the real downsides for, say, early theater or the very first films? Well, that's the key thing. These early organic adheses, they had built-in limitations, big ones for any kind of production. They were hygroscopic. Fancy word basically means they soak up moisture.

Ah, right. Not good. Not good at all. Imagine a prop or maybe some costume detail. A humid day. A sweaty actor. Cazard. Exactly.

The glue shrinks, gets brittle, maybe discolors. Your whole illusion just falls apart. Mid-show. Fish glue was especially bad for that. So that instability, that must have been the push towards final. something better. Precisely. That inherent unpredictability drove the search for synthetic alternatives. Filmmakers needed reliability, consistency. Which brings us to the early 20th century. Yeah. A massive shift, right? We start moving away from just using what nature provided.

Synthetics arrive, plastics, resins. It's a whole new ballgame. And it's wild how World War I and World War II just accelerated everything. The demands of war really pushed chemical research, didn't they? dramatically. And that had a direct impact on adhesives. A really pivotal innovation was something called the Tago glue film, patented in 1929. Cago glue. Well, it was special about it. It was a dry glue made from phenol resins, totally different from the traditional wet glues that, like we said, could go bad or be really inconsistent. Okay, dry glue. So more stable. Way more stable. It offered, and this was huge, unlimited shelf life and consistent quality. Right. Think about the film industry starting up. They needed things to be repeatable. Reliable props, reliable sets.

This kind of synthetic glue allowed for much greater precision, less guesswork. It basically introduced predictability into prompt making. Exactly. A huge step forward. So the wars pushed the boundaries and then when things settled down, did that chemical knowledge just flood into civilian uses? Like, did we get a ton of new glues there? Absolutely. The post-WII era was an explosion. Adhesive diversity specialization, it all took off,

driven by constant progress in industrial chemicals, polymer science. So what kind of new categories emerged? Well, a big one was pressure sensitive adhesives, PSAs. Like tape. Sort of, but much more advanced. The marble is they bond with just light pressure, no solvents, no water, no heat, easy. Okay. And they could be formulated for permanent or removable uses.

Think about that on a film set. Oh, wow. You could stick something up temporarily. Exactly. Stick a prop somewhere. Decide it's wrong. Peel it off cleanly. Stick it somewhere else.

No damage. No residue. Bostick makes some great ones now, waterborne, UV acrylic, easy removal is key. That must have saved so much time and money and allowed for more flexibility and design. Totally. It unleashed a kind of creative spontaneity, changed how fast you could try things out. Dow also makes silicone PSAs that are great for high temps. Okay, what else came out of that post-war boom? Hot melt adhesives, glue guns basically, but industrial strength.

They're 100% solid, you heat them up, they melt, you apply, they cool, and cool, bond instantly. Super fast. Big productivity boost on set. Plus they generally have lower VOC's volatile organic compounds, so safer air in studios. And versatile. Incredibly. Metals, plastics, wood, fabrics. Polyurethane hot melts, PURs are particularly good. Great thermal stability, flexible. They even cure a bit more with moisture from the air. So for film props, that means quick assembly and they hold up under hot lights or action. You got it. A huge efficiency game. Any others we should know about. Silicone adhesives definitely deserve a mention.

Their big thing is high temperature resistance, plus they're conformable and strong. You can get adhesion on demand at room temperature without fancy equipment. So for really tough jobs. Exactly. Specialized stuff where you need extreme durability, maybe under really harsh conditions onset, like something that needs to survive being near pyrotechnics or submerged. It's amazing. So these specialized synthetics really grew alongside the complexity.

of filmmaking itself. Directly correlated. They gave filmmakers the tools to push boundaries, make things faster, make things possible that just weren't before. Okay, let's switch gears. Let's head over the makeup trailer. Adheses are just critical there for transforming actors, right? Absolutely fundamental. Character creation often literally hinges on them. So what's the old standby, the one that's been around forever? That would be spirit gum, a true theater classic. We're talking documented use since the 1870s. Wow, really? Yeah. It's basically alcohol, SD. Alcohol 35A is typical and a resin. Originally mastics, maybe shalac now, some ethyl acetate. How why has it stuck around, pun intended? Huh. Well, it dries flat, almost

invisible. That's crucial for looking natural on camera. And it holds lightweight things, securely lace beards, mustaches, small prosthetic pieces. But it lets the actor move their face. That's the genius. It's durable but flexible. It moves with the actor's expression so they don't look like they're wearing a stiff mask that would totally kill the illusion makes sense did it have to change for things like hd cameras it did adapt they developed things like tv spirit gum which has a matter finished to reduce shadows from say the lace edge of a beard wow and spirit gum pee is stronger for performers who sweat a lot or work in high humidity doesn't go white so even the classics evolve yeah cool what came next you mentioned prosaid earlier the original sounds important it was a huge leap

Prozade has a fascinating backstory developed over 30 years ago by Dr. Alfonso Dimino But not for movies initially It was for medical prosthetics attaching artificial limbs and things Oh interesting So it was designed with skin contact and mind

From the start Exactly and that medical origin is key It means it's non-toxic, non-iritating, completely water-based It's FDA approved For actors wearing makeup for 12, 14, 16 hours Safety and comfort are paramount Absolutely

Absolutely. And how does it perform? It dries clear. It's totally waterproof, very strong. But crucially, it stays flexible. That's the magic. Prostetics move naturally with the skin. So that's why it became the industry standard. Pretty much. It's incredibly versatile, too. Attaching foam appliances, masks, horns, big foam latex pieces, gelatin, encapsulated silicone. It handles it all.

You mentioned Pax paint earlier. Right. You can thicken prosaid to make Pax paint. Makeup artists use that to blend edges, fill seams, even paint on realistic scars or textures directly onto the skin or inside molds. It's also the base for prosthetic transfers. Transfers, like temporary tattoos, but 3D. Sort of, yeah. It streamlines applying complex pieces.

Think about the zombie makeup in the Walking Dead. Oh, yeah. Or the Navi and Avatar. The silicone bodies in the Matrix, Drax's tattoos and scars and Guardians of the Galaxy. Those were transfers based on prosaid. It's everywhere. Incredible. Okay, next up, liquid latex.

The shapeshifter. What's its deal? Liquid latex is super versatile. Makeup, body paint, mask making, casting. What's it made of? It's basically natural rubber latex, suspended in water, usually with a little ammonia to keep it stable on the shell. That's key property.

Shrinkage. It shrinks about 3% when it dries. That tightening creates this amazing second skin feeling. It makes prosthetics look really integrated, very realistic, especially for subtle changes. How do artists use it? Lots of ways. Yeah. Building up texture, you can mix it with cotton or tissue to make scars, burns,

sealing the edges of latex prosthetics, casting new appliances, even as an adhesive for light things like zippers on costumes. How do you get it off? You just peel it off usually. Water doesn't reactivate it once it's dry. But latex allergies are a thing, right? A big thing. That's a major consideration. Latex allergies are common, and the ammonia can be irritating, especially to the eyes. You need good ventilation. So that pushed innovation, too. Definitely. The allergy issue was a big driver for developing alternatives like silicone and gelatin-based appliances and adhesives, safer for more actors.

But latex was still huge for things like the White Walkers and Game of Thrones, lots of classic zombie looks. So we've got the classics, the workhorses. But surely there were even more specialized glues for really tough film demands. Longwear, sweat, HD cameras. Oh, absolutely. The industry has a whole toolkit. Ben My prosthetic adhesive, for instance. It's strong, water-based, known for being durable and sweat-resistant. Great for latex pieces, clown noses, sticking on little things like rhinestones. Okay. Then there's Graftobian Pro Adhesive. This stuff is really strong.

It's a waterproof, medical-grade acrylic emulsion. Dries clear, super powerful, but still flexible bond. Who uses that? Movie studios, haunted houses, anywhere you need prosthetics to stay put through hell or high water, basically. 16-hour shoot days, intense action, swimming. It works great on foam, latex, gelatin, silaton appliances. It's usually applied as a contact adhesive coat both surfaces. Let them get tacky, then press.

It needs a specific remover, though. So these are the heavy hitters for modern film makeup. Tailored solutions for specific tough challenges. Exactly. Making sure every detail holds up, no matter what the scene demands or how close the camera gets. Right. Okay, let's shift focus again.

Away from actors toward building the actual worlds, props and sets. glues must be just as vital there. Absolutely critical. From the tiniest prop detail to massive set structures. Let's start with the everyday hero. Hot melt adhesives. Glue guns.

Indispensable. Their main advantages are speed and versatility. They're thermoclastic polymers, stuff like polyurethane, EVA, polyolephins. Yeah. Melt in the gun cool and hardened fast. Seconds sometimes. That speed must be crucial on set. It's a huge driver of efficiency.

Quick assemblies, quick fixes, prop breaks right before a take. Glue gun to the rescue. Plus, long shelf life, fewer VOCs, safer environment. And they stick to lots of things. Wood, plastics, fabrics, foam. Really versatile. But here's a cool thing prop makers do. You can shape the hot glue while it's still warm.

Oh, yeah. Like what? Create textures. Dripping goo or wounds, maybe alien horns or tentacles, monster fins. You can sculpt with it, basically. Adds instant detail. Cordless guns make it even easier and safer now, too. That's clever.

Okay, but what about when you need serious strength, when things absolutely cannot fall apart? That's epoxy territory, epoxy adhesives and resins. They're usually two-part systems resin and hardener that you mix, and they cure at room temperature into something incredibly strong and durable. So for bonding parts and take a beating? Exactly. General bonding for wood, metal, plastics, making sure props don't break during fight scenes or stunts. But they're also used heavily for casting. Casting?

Yeah, fabricating rigid or semi-rigid props. You can pour epoxy resin into molds. Sometimes it's filled with aluminum powder for extra strength or heat resistance, especially if you're making tools like molds for vacuum forming. Ah, so you can make multiple identical props. Precisely. Crucial for continuity if you need backups or if props are going to be destroyed on camera. Think about famous movie props.

The Maltese Balkan replica, Indies Crystal Skull, the elder one from Harry Potter, the Eye of Saran. Chances are epoxy play a big role in making those solid, detailed items. Right, epoxy builds the solid stuff. What about more every day, porous materials, wood, paper, fabric? For that, you've often got PVA glues, polyvinyl acetate, think standard white school glue, but often stronger formulations for professional use. Okay, the basic white glue. Why is it still used by pros? Well, it's economical, it's everywhere, and it works really well on porous stuff, like wood, paper, cardboard, fabric. It forms a strong, durable bond, dries clear or translucent, which is good.

Easy to use too, right? Super easy, water cleanup. You can even dilute it to use as a sealer or primer on surfaces before painting. The bond is semi-rigid, but has some flex. And importantly, once it's cured, you can sand it and paint over it.

The glue line disappears. So it doesn't mess up the final look. Exactly. Critical for props seen in close-up, like the replica Grail Diary from Indiana Jones. PVA was used to bond the leather cover to the cardboard structure. simple effective affordable okay got it now what about contact cement that sounds

intense yeah instant permanent bonds it is pretty intense it's a powerful usually solvent based adhesive very different application method also you apply a thin layer to both surfaces you want to join then you let the solvent evaporate until the surfaces are just tacky to the touch and you press them together and bam instant super strong permanent bond no clamping needed usually wow so when would you need that kind of speed and permanence on set. Rapid assembly is the big one. Especially with EVA foam.

You know, the stuff used for a cosplay armor, lots of movie costumes and prox, because it's light and easy to shape. Yeah, I've seen that. Contact Cement is the go-to for sticking pieces of EVA foam together quickly and permanently. Think about building orc armor

for Lord of the Rings. Lots of shaped foam pieces joined together. Contact cement makes that fast and strong. Makes sense? Any downsides? The fumes. Because it's solvent-based, the fumes can be strong, often toxic. Definitely need good ventilation or a respirator. Safety first. Also pro-tip.

Apply it after you heat-shape your foam because heat can reactivate the adhesive. Good to know. Okay, one more category. Spray adhesives, aerosol cans. Seems like they'd be good for big areas. Exactly. Fast and efficient for covering large or irregularly shaped surfaces. You get nice uniform coverage, which helps get a smooth finish. And they dry quickly. Really stick. Lots of things. Fabric, foam, plastic, metal, wood. wood, used for upholstery, sticking down insulation, trim, crafts, models, temporary signs. Very versatile.

Is there an advantage for film specifically? A big one is that they come in both repositionable and permanent formulas. The temporary sprays are gold for set dressing. Put up wallpaper, posters, fabric. If you need to adjust it, you can peel it off and restick it for a short time. Flexible. Very. And they have another role, too, beyond just bonding, aesthetic control.

Ever heard of dulling spray? Yelling spray. No. It's often a spray adhesive formulation, but it dries to a removable, cloudy, translucent finish. Cinematographers spray it on shiny surfaces, windows, mirrors, chrome props to kill unwanted reflections or glare for the camera. That's clever.

So spray adhesives help with both building and controlling the look of the set. Yep. Crucial for quick set changes, dressing large areas efficiently, and maintaining those high visual standards. So when you step back and look at it all, all, this whole journey of adhesives in Hollywood, it really highlights this deep symbiotic link between materials, science, and, well, cinematic art. Yeah, it really does.

From those ancient, basic glues to today's super specialized synthetic polymers, adhesives have always been the invisible backbone. They make the illusions believable. And the history shows this constant push, right? Overcoming limitations, often sped up by things like wartime needs, all serving the goal of making better movies. Precisely. It's just incredible to think about the sheer range.

Yeah. Special effects, makeup changing actors, keeping them safe, making it look real, and then props and sets the speed, the strength, the final look. They're involved in everything. They really are the hidden heroes, like you said. Which brings us to a final thought, maybe for you, our listener. As movies keep evolving, as audiences expect more, as techniques get more sophisticated, the demand for new adhesives isn't going away, is it? No, probably the opposite. Right. We'll need glues with maybe even better flexibility for robots or creatures, more durability for insane action sequences, maybe even smarter glues, glues that are kinder to skin for longer prosthetic wear.

So the innovation continues. It has to. So the question is, what's next? What future breakthroughs in adhesive science might unlock the next big leap in movie magic? What do you think filmmakers will be sticking together in 10, 20 years? That's a great question to ponder. Thank you for joining us on this deep dive into the, uh, surprisingly sticky world of Hollywood adhesives. Hopefully, you've gained a new appreciation for the science behind the spectacle. Yeah, next time you watch a movie, maybe look a little closer. You might just appreciate the unseen science holding all that Hollywood magic together.