Quite fascinating - although I understand that Real Photographers may not like Vanterblack:
https://www.dpreview.com/news/402003...s-in-the-world
Paupers might be interested in a mere 99.5 per cent absorbance from KoPro.
P.S. it occurs to me that said materials don't help much if one's monitor puts out some cd/m2 at 0/255 input or if some white shows through the black splodges in your print ...
... e.g. how black is black?