This chess board is designed for dual extrusion printing in two colors. The two files, BoardQuarterBlack.stl (or optionally BoardQuarterBlackScrews) and BoardQuarterWhite.stl, for the black and white squares (or whatever colors you want) must be merged in your slicer, and together they produce one quarter of the board. The joiner clips, or optionally screws, hold the quarters together with a tight press fit. The board quarters are printed face-down, so the finish will be as smooth, or as textured as your print surface.
Added: A version of the black file that uses M3x10mm or M3x12mm screws and nuts to join the board quarters. In your slicer, merge the BoardQuarterBlackScrews.stl file with the BoardQuarterWhite.stl to make a board quarter that can be held to other quarters with screws instead of the friction clips. This means you don't have to print the joiner clips, but you'll need 8 screws and 8 nuts for a standard 8x8 board. The screw option makes assembly much easier.
The squares are 40mm (1.575 inches).
The total board size is 320mm square (12.6 inches square).
There are four files: one for black squares and frame using joiner clips, one for black squares and frame using screws, one for white squares that is used with either of the "black" options, and one for the clips that hold the board quarters together, which aren't needed if you use the screw option.
Since the resulting merged 1/4-board prints are all identical, and the clips or screw holes are identical, this board may be extended infinitely in 16-square (1/4-board) increments for use in games that you may invent.
This was designed for 0.5mm nozzles. The clips are a tight fit. I used an arbor press to fully seat them. The clips may be scaled in the X and/or Y directions (but don't scale the Z) to make a better fit with your print settings.
The photo shows the board three-quarters assembled, the fourth quarter being printed, and the joiner clips. The bottom of the assembly is shown so you can see where the clips go.
Remember: A proper chess board has a white square in the right hand corner of the board for both players, and the queen goes on the square of her color.