I interpreted this along the lines of it not being a pigment, rather it's black because something about it's physical structure at a small scale causes light to not reflect back. Adding a thin coating of gold would not necessarily change that structure so it would continue not reflecting light.

^ pure conjecture

A layer of very thin gold can be transparent.

That article has a paper link: https://doi.org/10.1002/adsu.202400184

Also, the black parts there really didn't look that dark.

It's probably a combination of the surface being black in colour (charcoal), plus a surface texture that absorbs light.

It brings to mind the way feathers and insects often have brightly-coloured parts that aren't due to pigment but rather the microstructure preferentially absorbing/reflecting specific wavelengths, giving a colour.

https://en.wikipedia.org/wiki/Structural_coloration

Similarly, I wouldn't be surprised if the microstructure is tuned to work best (lowest reflectance) in the visible light range.

EDIT: limited wavelength range also applies to other "super-black" materials https://en.wikipedia.org/wiki/Super_black#Technology

Well they say it doesn't rely on pigments, so I'm inclined to think it uses some sort of nano-structures, like "improved" vantablack. Like a forest where light goes in, but just get's scattered long before it can make its way back out. Ben did a really nice video about that homemade stuff, including (of course) some electron microscope images.

https://www.youtube.com/watch?v=Xr1AiExSAnU

Two things are at play, the lignin (light absorbing) is emphasized and the cellulose is burnt away (light reflecting), and it seems this combined pretty unique lattice system (they use a similar synthetic system when producing regular ultrablack paint but the natural one appears to be more complex) create the blackness.

Check the paper, especially figure 5: https://doi.org/10.1002/adsu.202400184

Burning the end-grain wood makes a particularly complex porous structure that minimizes the chance of reflected light escaping ("velvety").

I read it as "N-xylon", where "ξύλον" is wood in Greek.

A room where all the walls, floor, and ceiling are made of this would be pretty disorienting, wouldn't it? Even with a light source that let you see all the people in the room, wouldn't it just look like you're all in a pocket dimension?

How much more black could it be? None. None more black.

Here [0] is the paper in question, it has a chart that shows the reflection rate of this one at around 0.3 - 2%; the paper itself has the following quote for the competitors:

> Far lower reflectance values have been achieved with materials containing aligned carbon nanotubes (CNT), for example a low-density CNT array (0.045%),[11] the coating Vantablack (0.035%)[7] and a CNT-metal foil (0.005%).[12] The current holder of the “record” for a low reflectivity material (<0.0002%) is an ion-track micro-textured polymer with anti-backscatter matrix.[13]

So they're arguing that it's on-par with Vantablack but not the newer materials.

[0] https://onlinelibrary.wiley.com/doi/10.1002/adsu.202400184

Probably less carcinogenic.

If my understanding is correct, Nxylon is lighter than Vantablack (in terms of weight) but reflects slightly more light. This means that it is less effective than Vantablack at absorbing light.

I think combining Nyx (dark) + xylon (wood) makes perfect sense in a vacuum.

But these researchers have doomed themselves to forever explaining that no, they didn't misspell nylon, and yes, this is something completely different.

The name and the replies to parent remind me of why you should definitely check any name ending '-lon' that you think is a good idea to use: http://news.bbc.co.uk/1/hi/uk/2222783.stm

I'm surprised they went for nxylon to combine nyx + xylon rather than, you know... nyxylon

It's already trade marked

From the article: "The team named and trademarked their discovery Nxylon (niks-uh-lon), after Nyx, the Greek goddess of the night, and xylon, the Greek word for wood."

Not sure why they didn't call it Nyxylon.

"Please don't post shallow dismissals, especially of other people's work."

https://news.ycombinator.com/newsguidelines.html

[flagged]

Neither of those generally results in <1% light reflectance however.

Light doesn’t normally cut through solids, doesn’t mean lasers aren’t a useful or unexpected technology.