Without a reflectance/absorptance value it is hard to say but Black 3.0 with 99.6% is nowhere near close to Vantablack with 99.965%.
Edit: People are quoting 99.95% for Black 4.0 which is impressive!
Edit: People are quoting 99.95% for Black 4.0 which is impressive!
Curious, under what circumstances will this 0.365% be practically important?
The difference is 0.4 to 0.035
An order of magnitude more light reflected.
These blacks are "black" in that they absorb visible light. How or if they absorb IR light (the bulk of heat energy) is a different story. They may be totally reflective in IR. But yes, something that is more black in visible light is probably also more black in IR. But also remember that black objects are also better at emitting IR.
I remember being told that white objects reflect heat, which is why white clothes and white buildings are better in hot, sunny locations. I thought the reverse would be true for black. Thanks for educating me!
For example our hearing range is 20-20000 Hz, yet we can perceive a 20 Hz sound as different from a 40 Hz one, the difference between them being 20 Hz which is 0.1% of our hearing range.
https://cdn.discordapp.com/attachments/824109424255434803/88...
Seems there is a lot to go beyond 99.6%
I don't know what the absorption value of the black velvet is though. I am curious how Black 4.0 would compare to black velvet.