Nano–texture glass
What exactly is this tiny cutting–edge tech?
When Apple unveiled the Pro Display XDR, it also introduced a new kind of screen technology. But it wasn’t a new kind of LED lighting or a new image processor. It was glass. Very, very expensive glass: an extra $1,000 on top of the $4,999 price tag.
Apple calls it nano–texture glass and it’s also available in the latest 27–inch iMac, where it’s a $500 extra. So what does it do, and why would you want it?
GLASS! AH–AHHHHH!
For many years, Mac laptops had matt screens, but the popularity of the iPhone and of PC laptops with glossy screens helped persuade Apple that glossy displays were the way forward. Speaking in 2006, Apple portables product director Todd Benjamin said having a glossy display “means colors are much richer — they look great,” and that they were particularly good for watching DVDs. They also looked more exciting in retail environments.
But glossy displays are also very reflective. If you’ve ever used your MacBook outside on a sunny day or tried to work on your iMac when a shaft of sunlight hits the screen, you’ll know how difficult it can be to see what’s on screen. Pro users in particular weren’t happy about this because in many professions accurate color and high contrast is essential and reflectivity spoils that visual fidelity. In an attempt to mollify them, Apple offered anti–glare coatings as options in some of its 2009 MacBook Pros.
That wasn’t entirely successful. In 2014 it emerged that there were problems with the anti–reflective coating on MacBook Pros, an issue dubbed “staingate” because the coatings on many devices began to degrade or delaminate, leaving very visible and unremovable stains on the display. After two years of complaints, Apple introduced a screen replacement program for affected laptops.
ART OF GLASS
Apple has tried other things to reduce reflectivity. Its laminated displays — which you can see most clearly (excuse the pun) in the iPad Pro, iPad Air, and iPad mini — have less of a gap between the display panel and the front of the glass. This enables thinner displays and makes reflectivity less of a problem because the pixels appear to be sitting on the surface of the display rather than underneath it. It’s certainly an improvement, but unfortunately it’s not perfect: ultimately no matter how clever the display tech, if
you’ve got a sheet of glass in front of it, you’re going to get reflections.
Or at least you will if you don’t think differently about the glass itself…
Everything you can see reflects light: if it didn’t, you wouldn’t be able to see it. But some things are more reflective than others. A glossy magazine page appears to be more shiny and reflects more light than a matt one of the same weight. That’s because the smoother and flatter the surface, the more “specular” reflection you get. Specular is from the Latin word for mirror, and you get it when light is reflected from a smooth surface such as a normal sheet of glass.
DIFFUSE THE LIGHT
But specular isn’t the only kind of reflection. There’s also diffuse reflection, which is when the rays of light are reflected in lots of different directions. The rougher the surface, the more diffuse and less specular reflection you get — so if you can make a smooth surface rougher, you can make it less reflective.
Anti–glare coatings provide that roughness, but as we saw in “staingate” they have their problems too. They also affect the quality of what you can see, as Apple explains: “Typical matt displays have a coating added to their surface that scatters light. However, these coatings lower contrast while producing unwanted haze and sparkle.”
What if you could get the same anti–reflective effect without the downsides by etching the glass instead? Well, that’s exactly what nano–texture glass does.
NANO, NANO
With nano–texture glass, Apple etches microscopic “nanostructures” into it. The “nano” bit means that the structures are measured in nanometers, and a nanometer is one thousand–millionth of a metre.
By covering the glass with nano–scale etchings, nano–texture glass can diffuse visible light without being visible to the naked eye and without causing the visual effects of anti–glare coatings.
That etching is also the reason Apple strongly advises you to use its special cleaning cloth: it says you should “never use any other cloth to clean the nanotexture glass.”
Why not? Apple doesn’t say. But it seems likely that everyday cleaning materials might either deposit tiny fibres that could clog up the etched structures or that the etchings are particularly fragile and prone to damage. Either way, it isn’t a job for Windex. CARRIE MARSHALL