This pair of chalkboards features a silk-screened set of double lines on the front and a grid pattern on the back of both boards.  The boards measure 50 cm x 32 cm (about 20" x 12") and take the chalk very well, however we recommend conditioning them before your first use by simply rubbing them all over with chalk dust.  They will get even better with more use.  Also available is Chalkboards Set 1 (single lines), and Chalkboards Set 3 (blank).