[sjackso]

If you're interested, here's a thread of telescope nerds discussing that exact usage: https://www.cloudynights.com/topic/692954-how-black-is-the-b...

[notJim]

  Well... the price was reasonable, something around $26 for
  150 ml bottle including shipping to Pennsylvania (USA), and
  I am not Anish Kapoor so I decided to give the paint a try.

Since many of us are amused by the Anish Kapoor situation, I wanted to highlight this wry comment from your link.