Centura lists Castle Mosaics Grey in the Castle Mosaics range: a 12" x 11" mosaic. Centura rates this one for walls, not floors, which puts it in backsplash, surround and feature wall territory. One box contains 18 pieces, enough for 16.66 sq ft, or 0.9256 sq ft a piece. Mosaic sheets are mounted on mesh, so the pattern stays aligned while it is set and the sheet can be cut to fit an edge.