Economical, unframed lap board features a blue XY axis dry erase grid on one side and plain dry erase on the other. Bold lines separate board into quadrants each 14 squares by 10 squares; total grid is 28 squares by 20 squares. Individual squares measure 3/8" x 3/8". Boards feature non-ghosting dry erase surface with rounded corners and smooth edges for safety and comfort. Durable hardboard backing is warp and chip resistant. Measure 9" x 12" x 0.125". Pack of 12.