Musou - Worlds Blackest Black Paint
After independent testing, we found that Black 3.0's actual light absorption rate is actually around 97.5%.
Although Black 3.0's and Musou Black Paint's absorption rates are relatively close (Black 3.0 = 97.5%, Musou Black Paint = 99.4%), the 1.9% difference between the two paints makes a huge difference, as you can see in the photo.
An alternative way to explain the difference in blackness is that Black 3.0 reflects 2.5% of light, while Musou Black Paint reflects only 0.6% of light. This means that Musou Black Paint is more than 4x blacker than Black 3.0!