If you want black keycaps, just take your keyboard with printed keycaps, grab some isopropyl alcohol and wipe of the printing. Look, you just saved your time and money.
BurnTheDeadThey are PBT keycaps. Many enthusiasts have laser etched or doubleshots anyway.
And you can't find Blank Black PBT keycaps anywhere else. PBT is the highest quality material for keycaps and well worth the price.