I have the unmarked "ninja" caps from Ergodox, which are PBT plastic, DCS profile and sculptured. They are made by Signature Plastics
As a note, PBT is more highly regarded than the usual ABS. PBT is Polybutylene Terephthalate. It is harder, stiffer, and more durable than ABS. It will take longer to become shiny than ABS (if it ever does). My PBT keycaps are matte, which I like but some people prefer shiny.
The "endgame" blog article above shows his keyboard with "GMK Dots" from Novel Keys. Nice, but I don't see these available any more. I asked Novel Keys about them and the answer was, "sorry, no longer available".