The Cover-Up

How screen protectors became a part of our lives, and the weird reason some early cathode ray tubes needed them.

By Ernie Smith

Today in Tedium: You know something I always kind of wonder to myself? Many phones, generally of the Android variety, often come with very basic screen protectors directly on the screen; why are they not as good as the ones you can buy on Amazon for like $8? Screen protectors have become a big part of people’s lives—you are literally touching them thousands of times a day, possibly more. And yet, when you get the one from the manufacturer, it’s often so weaksauce that you need to buy another one that is going to last more than like two weeks. I guess it’s with this state of affairs in mind that I got curious about screen protectors, where they came from, and whether older types of screen technologies, like cathode ray tubes, needed stuff like this. The answer was literally explosive, or to be more exact, implosive. Today’s Tedium talks screen protectors. — Ernie @ Tedium

Today’s GIF is of an Apple Store employee installing a screen protector using a specialized device. More on that below.

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Vintage Television

(Africa Studio/Adobe Stock)

Why early televisions needed “screen protectors”: It wasn’t because you needed to touch them

In the early days of screens entering our lives, the concerns about the screens were different from what they are today. As the famed YouTuber JerryRigEverything puts it, we’re concerned about scratches at a level 6, with deeper grooves at a level 7. (Shout-out to Mohs Hardness Scale.)

We didn’t need to worry about touching our screens, really. Rather, we needed to think about degaussing them, about ensuring that the surface of the screen stayed intact, and wasn’t negatively affected by dust. And since we were talking about a different technology than the LCD used, the needs were simply different.

And during the early years of the television set, our living room hubs needed a product very similar to a screen protector, albeit one that had a different purpose.

See, early cathode ray tubes faced a risk of implosion. After all, happening inside that good ol’ electron gun is a vacuum effect that put them at a small-but-constant risk of imploding.

If the word “imploding” gives you memories of our piece on Canada’s exploding soda bottles, you are thinking in the right direction. Imagine your family in the living room, watching an episode of Ed Sullivan or Mr. Ed, and all of a sudden, the screen goes awry, sending shards of electron-splashed glass violently flying everywhere, and you kind of get the idea. (If Stephen King had written a short story with basically this plotline, randomly exploding TVs everywhere, I would not be surprised.)

This facilitated the need for screen protectors on early television sets, but rather than protecting you from breaking the screen, these protectors were trying to protect the screen from breaking you. As a 1964 New Scientist piece put it:

Because they are large evacuated vessels, cathode ray tubes can implode, just as a toy balloon can explode. In practice they hardy ever do, and the very few implosions that do occur each year (probably never running into two figures) are often the result of accidental mishandling of the picture tube, which is inherently extremely strong. Yet the one in many millions chance that a viewer might be hurt by flying glass has made it necessary to fit a clear protective guard between the tube and viewer into every receiver that is made. These guards have taken many forms, including flexible and moulded plastic, armour-plated glass, and heavy curved sheet glass glued to the front of the tube.

So early television screens had “implosion guards,” which existed on the off-chance you got a defective unit or the repair didn’t go very well. Talk about entertainment.

Exploding television set

The homeowner’s frustration sells it. (The Hammond Times/

You may think that it’s unlikely, but I did a search for “exploding television sets” and immediately found stories of cathode ray tubes shattering throughout living rooms in the late 1950s and early 1960s. In one case, from Indiana, the set spontaneously exploded in the middle of the night, causing a situation that the homeowners describe as being similar to an “atom bomb.” A common thread in some of these situations is that the picture tube had recently been changed. (Perhaps the TV repairman forgot the implosion guard?)

So, all this meant that television sets needed screen protectors, though they had a much more imposing name back then. These guards, made of plastic or glass and appearing as early as 1953 in the United Kingdom, had many of the same types of issues that you might see with a screen protector on your phone. Back to New Scientist:

Conventional methods of implosion protection can be seen to suffer from many disadvantages, such as the disturbing occurrence of multiple reflections of objects and lights in front of the receiver, or the penetration of dust into the inaccessible space between the tube faceplate and the guard. (This second problem, particularly troublesome in industrial districts, is aggravated by the fact that the tube acts as its own electrostatic precipitator.)

Added unwanted reflections and a risk of dust getting between the layers? That basically describes the problems with most screen protectors.

So, how come you’ve never heard of an implosion guard? The reason, essentially, comes down to efforts to improve the technology, so the added layer wasn’t needed at all, or at least wasn’t obvious to the consumer. As early as the 1960s, companies were attempting to make television sets more resistant to imploding. Fore example, Owens Illinois, a glass-maker once associated with Owens Corning, received a patent in 1966 for an “implosion resistant cathode ray tube” that relied on mounting elements to hold the screen in place, one of many patents the company received in an attempt to fix this knotty issue.

Many of the solutions that became popular used a similar method to cut back on the stress that the monitor faced. Many later CRTs have this surrounding bracing, which helps take the pressure off the glass itself and even allows the designs to be less curved. As a result, the real reason that the “screen protector” was there no longer became necessary.

Years later, screen protectors found another television use case, but for rear-protection televisions that were used in big-screen settings before the LCD panel, but those used different technology that didn’t face concerns of implosion.

But there was one type of CRT-style panel that benefited greatly from a smartphone-style screen cover, and it directly inspired some of the first patents for handheld-device screen protector technology.

That’s right—we’re going to talk about “fish finders.”

“Keep in mind that the way any ‘scratch remover’ works is to buff down the surrounding surface so that it’s level with the deepest part of the scratch. This means that the most effective scratch removers also tend to be the most abrasive, requiring subsequent treatment with milder products in order to remove finer scratches left by the scratch removers themselves.”

— Dan Frakes, a former senior editor at MacWorld, offering advice in a roundup of scratch removers for iPods. Notably, early models of the iPod used snow-white plastic that was prone to heavy scratching on the screen, which made the devices quickly lose their luster. One of the offered solutions in the story was, I kid you not, toothpaste, which had been offered as a bit of a home remedy to the repair issue. (Per Frakes: “Sadly, I can’t recommend it, as—and this is a bit frightening considering that we use this stuff on our teeth—it’s simply too abrasive.”)

Fish Finder

An example of a fish finder that uses a CRT. (via eBay)

How the fish finder inspired the modern smartphone screen protector

There was a time that we didn’t put our grubby fingers on screens, that we used an interface to control them. But gradually, that began to change.

Part of the reason for this, simply put, is the rise not of the touchscreen, which did later become enough of a revolution that screen protectors would be, but of the stylus. The modern form of what we would think about as a screen protector today first emerged to support the plastic devices that allowed us to hit items on screens.

While I’m having trouble uncovering screen protectors for the Apple Newton, which has a decently tough screen, This kind of approach started gaining steam during the era of Palm Pilots and Windows CE devices, devices that were heavily reliant on styluses. (Palm specifically sold screen protectors for its devices, which you can still find on eBay.) There was a real need for them, because, after all, if you dug in too deeply on the screen, you could accidentally cause permanent damage.

Just as with television screens, there are a few patents for screen-protection technology, with the most relevant including an “antisoiling hardcoat,” applied for in 2000 and granted in 2005, that was developed by 3M specifically for PDAs. But the patent filing seems to suggest inspiration from some unusual sources. As prior art, the filing specifically cites an acrylic screen protector for a rear-projection television, as well as one for a “fish finder,” a CRT-style sonar-tracking device that does what it says on the tin.

Fish Finder Patent

Imagine inventing this film for fish finders, only to find that your invention was used by tens of millions of people in a completely unrelated context three decades later. (Google Patents)

The fish finder screen protector, which relies on a transparent vinyl applicator, is very close in use case to modern soft-shell screen protectors, which I think says a lot about how technologies for obscure or even unknown use cases become very common over time. As that patent filing states:

In view of the foregoing disadvantages inherent in the known types of protective shields now present in the prior art, the present invention provides a viewing screen protective shield wherein the same may be readily and efficiently securable to a viewing screen typically subject to destructive environmental conditions.

In other words, it absolutely makes sense that fish finders were first-movers on this kind of screen protector, because the setting in which a device like this is used is often subject to elements—wind, sun, sand, and so on—that could degrade a screen over time. While not exactly the same use case as a smartphone, it certainly says a lot about why it eventually made the leap.

Screen Protector

A drawing from a screen protector patent developed by 3M in the early 2000s. (Google Patents)

The fish finder design was ultimately improved upon by Samsung, in a patent first applied for in 1997 and granted in 2000, that attempted to fix one of the problems of the fish-finder screen protector design—the fact that it could create hard-to-remove bubbles. While not designed with touchscreens in mind as the 3M patent filing was, it nonetheless described how screen protectors would ultimately be used. As that patent filing notes:

The outer coating preferably has a hardness which is less than that of the screen but more than the hardness of the face of the image display device. Reduced scratching can thereby be provided. The outer coating may also include a friction reducing agent to further reduce scratching.

Given that tools like PDAs and pre-iPhone smartphones were generally not lower-end consumer products that moved out of professional settings, odds are that the first time a “regular” person who didn’t work in the corporate world might have encountered a screen protector wasn’t with a smartphone, but a video game console. The Nintendo DS, dating to 2004, was perhaps the first mainstream portable touchscreen device that was designed to be used with a user’s grubby fingers rather than just a stylus, which meant that there was a clear use case for screen protectors on those.

Another device that might have inspired the widespread use of screen protectors was the iPod. While iPods didn’t use touchscreens before the iPhone came out, in many ways, they reflected the fact that people didn’t want their screens to become all scratched up over time, given how much money they spend on these devices. As noted in the quote from MacWorld above, techniques were basically everywhere that described methods to help protect the screen, including some home remedies. In particular, the original iPod nano was an inflection point, because it was a device that was kept in a pocket with keys or other scratchy devices, and when it got scuffed up, people got mad.

One could imagine Steve Jobs getting one look at the angry comments about the first-generation iPod Nano on Apple’s forums, knowing that the iPhone was in the works, and deciding that tempered glass was the right choice going forward. Cracked screens aside, that was probably the smartest decision he ever made.

That was, of course, good for the screen protector industry. After all, glass may be more resistant to elements, but the scratches are often much harder to remove and even prevent than plastic.

And to think—we have the creator of a fish-finder screen protector to thank for developing the general idea.


A term for oil resistance that is commonly used in reference to smartphones. Most modern smartphones contain an oleophobic coating designed to prevent oils from sticking to the device, which aims to make the device fingerprint-proof. One way to check to see how good your coating is involves putting drops of water on the device; if the coating is active, the beads will stay separated; if it’s lost some of its luster, the water will pool.

If you look on YouTube, you will find more than a few people who are impressed with Apple’s elaborate system for putting screen protectors on new phones. Using covers produced by Belkin and a device that looks vaguely like a panini-maker, the process is multi-step, bubble-free, and fool-proof.

It almost makes you wonder the obvious question—why does Apple not just put these high-quality things on the screen by default? And not the cheap film that comes off after five minutes, either; long-term screen protectors that are built to last. After all, this will look significantly better than any regular user doing this. Try as you might, whether with tempered glass or with a layer of PVC, you are always going to miss some detail that is going to put a tiny speck of dust under your screen for the next year, slowly driving you mad or leading you to have to reapply the protector.

Apple’s factories are often fairly clean. Hell, so are their stores. Your bedroom is probably a pig sty in comparison.

And the other thing you might be thinking: Is this screen protector thing a racket? Would we be better off not paying for these cheap covers and just taking our chances with the elements? Maybe not, but there are in fact alternatives, and they’ve been around a long time.

The DIY approach to protecting your screen involves a thick piece of packing tape or clear vinyl covering, dish soap, a pen knife, a credit card, and a little bit of pre-planning. You are essentially cutting the plastic to shape, with the hope that the material (whether via adhesive or static) sticks to the device long-term. Unless you are an expert cutter, odds are you will not be able to do more detailed cuts like a punch hole or rounded corners for your makeshift screen protector, but given the right shape, you can save a bit of money.

After all, the reason why there are so many random companies selling this product on Amazon and elsewhere is because it’s insanely easy to produce, so why not produce it yourself?

That’s the way the thinking goes, anyway. But one piece of advice to offer: Don’t go down the road of trying to buff down the glass yourself using sandpaper or car wax. Your phone isn’t built for it, and as a 2012 Popular Mechanics piece notes, nearly all of these techniques do basically nothing to solve the actual problem.

So maybe we are stuck buying cheap screen protectors from no-name companies on Amazon after all.


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Ernie Smith

Your time was just wasted by Ernie Smith

Ernie Smith is the editor of Tedium, and an active internet snarker. Between his many internet side projects, he finds time to hang out with his wife Cat, who's funnier than he is.

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