For most of the last 40 years, radar stealth has been shorthand for two things: enormous amounts of money, and secrets nobody outside a cleared facility was allowed to see. A B-2 Spirit runs about $2.1 billion a copy, the most expensive aircraft anyone has ever built, and the F-117 that opened the whole stealth story spent years as a black program before the public knew it existed. Making an airframe hard to see on radar meant controlled factories, exotic materials, and a budget only a handful of governments could write.
Star-Navi, a company based in Shenzhen, is now selling a version of that capability in a tub. Its XRAM-C Series is a sprayable radar-absorbing coating that, by the company’s own numbers, takes roughly half the reflected radar power off a coated surface, and it comes packaged the way you’d buy industrial paint: 1, 5, and 10 kilogram containers, applied with a spray gun. The Defence Blog, which first detailed the product, described it as selling “core technology by the kilogram.” That phrase, not the performance figure, is the part worth paying attention to.
What’s actually in the can
The XRAM-C line is a black-gray liquid you spray onto a prepared surface and let cure, and Star-Navi splits it into three formulas aimed at different radar bands. The XRAM-C105 targets the X and Ku bands, which is where a lot of fire-control radars live, along with the millimeter-wave sensors inside modern counter-drone systems. The XRAM-C112 goes after the S and C bands used by the surveillance radars that build the first picture of what’s in the sky. The XRAM-C113B trades peak performance at any single frequency for broadband coverage across C and X band, for an operator who doesn’t know which radar he’ll be hiding from.
The physics is the same physics every stealth program uses. A bare metal or composite skin bounces most of an incoming radar pulse straight back to the receiver, which is exactly what lets an operator find you, track you, and shoot at you. Radar-absorbing material sits on top and turns that energy into heat instead of reflecting it, so the return signal gets weaker and the target looks smaller than it is. Star-Navi’s published spec sheet, reported by The Defence Blog, claims at least 3.0 decibels of reflection loss across 8 to 12 gigahertz and at least 3.5 decibels across 2 to 6 gigahertz, at a coating thickness between 0.40 and 0.60 millimeters.
The company says the coating stays under 1.1 kilograms per square meter at the thin end, survives 250 degrees Celsius for 100 hours, and passes a 2,000-hour salt-spray corrosion test, which is the kind of number you quote when you want to sell to a navy as well as a drone shop.
Half a radar return sounds bigger than it is
Three decibels does mean what it sounds like. A 3 dB cut halves the reflected power reaching the radar. The trouble is that “half” is a far smaller deal in stealth than it is on, say, your power bill. Serious radar-absorbing treatments are generally reckoned to take 20 to 30 decibels off a return, and the math there is unforgiving. A coating that delivers 20 dB is handing back about one percent of the radar energy that hit it. Star-Navi’s 3 dB is still handing back roughly half. One of those makes you genuinely hard to find. The other makes you slightly harder to find.
For a sense of where the ceiling actually sits, look at the competition Star-Navi keeps getting measured against. A Turkish researcher named Yunus İnce has been developing a spray-on absorber called Kürşat 3.0, built around volcanic basalt and pumice, and İnce claims an attenuation figure of 43.2 decibels in his own testing, according to The Defence Blog’s earlier reporting on the Kürşat project. If that number holds up, it’s in the same league as the classified treatments on actual stealth aircraft. It’s also still a lab result, not something sold by weight with a spray gun in the box. That contrast is the honest frame for the Chinese product. XRAM-C is not a B-2 in a can. It’s a small, real reduction you can order online.
The barrier that actually fell
If the performance is modest, why does any of this matter? Because the expensive, secret part of stealth was never only the recipe. It was everything around the recipe. The treatments on advanced stealth aircraft need controlled manufacturing environments, specialized tooling, and depot-level facilities to apply and repair, which is a big slice of why the B-2 cost what it cost and why only 21 were ever built. Star-Navi’s entire pitch is that none of that applies to XRAM-C. Spraying a coating onto a prepared surface and curing it doesn’t require any infrastructure a drone maker or a military unit wouldn’t already have, and the packaging makes the point on its own: this is material sold by the kilo and applied at the unit level, not a factory process you have to buy your way into.
That’s the shift. Radar-signature reduction is turning into something you can do after the fact, to hardware you already own, with people you already have. Whether the coating delivers 3 decibels or 13, the genuinely new development is that the gate is open. The thing that used to need a cleared facility and a defense budget now needs a credit card and a respirator.
Where a few decibels start to count
A 3 dB cut on one expensive aircraft is a rounding error. A 3 dB cut on ten thousand cheap ones is a different conversation. The drones reshaping modern conflict aren’t exquisite platforms; they’re mass-produced and expendable. The American version of the type, the Shahed-class LUCAS attack drone, costs the Pentagon around $35,000 a unit and is built around commodity parts, and Russia and Ukraine field one-way attack and reconnaissance airframes by the thousand.
Shave a little detection range off each of those, repeated across a whole fleet, and you’ve complicated the picture for whoever’s running the air defense, even when no single drone is meaningfully stealthy.
That lands directly on the part of the problem that’s hardest to fix. Jammers and interceptors are useless until something detects the threat, and detection mostly runs through radar. The Pentagon spent four years and a lot of money chasing a counter-drone fix before an Army test pointed at software and existing turrets rather than a new platform for every base.
Those systems are tuned around the assumption that most drones show up as detectable targets, because radar stealth has been out of reach for the people building cheap ones. A coating that chips away at that assumption, even slightly, even unevenly, is a headache for a detection-first defense. And drones are colonizing every domain at once, right down to robots that sit on the seabed guarding cables, so the surface area of the problem keeps growing.
Stealth has been beaten cheap before
There’s a useful piece of history sitting under all of this. The one time a stealth aircraft was famously shot down, it wasn’t out-teched. On March 27, 1999, during the NATO air campaign over Yugoslavia, a Serbian battery from the 3rd Battalion of the 250th Air Defense Missile Brigade, commanded by Colonel Zoltán Dani, brought down an F-117 with the callsign Vega 31 using an S-125 Neva, a Soviet surface-to-air system already decades old at the time.
The crew leaned on low-frequency radar in short bursts, predictable NATO flight paths, and the absence of an electronic-warfare escort that night. The pilot, Lt. Col. Dale Zelko, ejected and was rescued. It was the first combat loss of a stealth aircraft, and it was managed with hardware far cheaper and dumber than the thing it killed.
The lesson then is the lesson now. Stealth was never invisibility. It was a reduced signature, optimized against particular radars, and there’s always a cheaper angle the optimization doesn’t cover. A coating tuned for the high-band fire-control radars in the XRAM-C105 would have done nothing about the low-band radar that found the Nighthawk in 1999. Lowering your radar return is genuinely useful. It has never been the same thing as disappearing.
None of Star-Navi’s figures have been independently verified, and they shouldn’t be read as anything more than what they are: a manufacturer’s spec sheet for a product it wants to sell. Spray a coat of XRAM-C on a quadcopter and you will not have built a B-2; you’ll have a drone that’s a little harder to see, on a good day, against the right radar. But the number that should bother anyone running a counter-drone program isn’t the 3 decibels. It’s the kilogram.
Radar-signature reduction has gone from a capability you design into a billion-dollar airframe under armed guard to a capability you order by weight and spray on in a tent, and that genie does not climb back into the tub.
