Hello! These pieces come loose with a printed key and letter codes imprinted on the back of the tile calling out the 8 shapes that comprise the pattern.
We do offer sheeting on request, but with the heft of some of the larger pieces in the Prairie Lattice pattern, we usually find that laying up tile with standard spacers works well.
Here's a photo example of an install in process (with spacers - click & enlarge for more detail):
North Prairie Tileworks
North Prairie Tileworks