It is not recommended to go below 2mm for wall tiles and 3mm for floor tiles due to the requirement of stress relief.
Tile floor no spacing.
How to lay tile without grout lines.
12 by 24 tiles can have some bow to them instead of being perfectly flat when set on the floor they ll have a slight arch.
Most floor tiles are 8 inches by 8 inches but larger versions are available.
It keeps moisture out of the substrate helps keep tile lines straight and.
Grout is a necessary and integral part of many tile jobs for several reasons.
For example floor installations should consider using larger grout lines for more traction.
Special types such as slate or quarry tiles often do not have edges uniform enough to look good with tight spacing.
The instructions for installing this tile state using tile spacers speaks of the grout lines suggested size being 3 16 so i would triple check to be certain that these are a self spacing tile as i see no where that that is listed as being the case on any site.
It follows that the maximum height of the arch will be midpoint of the tile or in your case at the 12 point of the long 24 edge.
Crater lake 3x12 design.
Where the tile is being installed.