Minecraft wiki entry for Printing, associated text: In the 3D printer, the structure is split into flat 3x6 areas. The colors and arrangements for each of these areas are put into multiple shulker boxes for ease of use. For larger prints, it makes sense to instead input the colors in the order they are interpreted. There is a "conveyor belt" comprised of flying machines that drops the powder on a set of synchronized flying machines to drop the powder into the printing area. By making the conveyor belt faster, the whole design can be sped up.