These marble textured chess pieces are standardized sizes as defined by the FIDE, the Fédération Internationale des Échecs or International Chess Federation.
See here for video: https://youtu.be/0DXSG8C0YfQ
The model shown in the video is printed in “copy mode” on a Snapmaker J1 IDEX printer with both colours printing at once!
Multiples of each piece are provided so that each piece within a set can have a distinct marble pattern (i.e. there are two each of the rook, knight and bishop pieces and eight each of the pawn pieces.)
The king and knights are provided with or without built in supports for the overhanging sections.