Carcassone is a tile-laying game. The 'game board' grows as the tiles are laid, in whatever direction the tiles fit. In our games there has been a continuing problem in keeping the tiles straight, and it can become a major operation if the 'board' has to be shifted if it nears a table edge. The Tile Grids each hold nine tiles in perfect alignment, and the grids snap together with small dovetail joints to grow the board in any direction as necessary. There are small raised ridges between each tile, but this doesn't detract from the game. A small game can be held by about ten grids, but a large one with many expansions could take 20 or more grids. The photos show a game as it expands over time.
This is pretty much a printer calibration object, as it extends from front to back on a Replicator platform, giving lots of opportunity for lifting corners. Your platform -must- be aligned. Let the platform cool a bit before lifting or the grid will warp. (If you do warp one, heat up the platform again and use something to press it flat.)
Printed at 0.2mm layer height, 100% fill.
The fit of the dovetail joints has worked perfectly for me, but the fit might depend a bit on your filament width. A bit of a trim with an x-acto knife might be necessary.
I've printed them in black and green ABS, and was thinking that the green would be less obtrusive, but my daughter has used both and prefers the black.