These multilayer mats are usable on both sides, with function and versatility in mind. the one-inch lines with two sets of corresponding numbers that are placed around the perimeter of the mat can be read left to right AND right to left - this means never losing your place or having to count backwards! This size is a perfect classroom or travel size, as it gives you plenty of room for larger project but you can still take it to class. The size is 24X36