OMNIGRID-Cutting Mat has a self-healing base .25" hash marks on all four sides 1 inch grid marks on all four sides and two bias diagonals; markings are in yellow. Cutting surface on both sides grids on one side. 1.5mm thickness. Mats are true full-size meaning an 18x24 mat has 18x24 measurements plus .50 inch salvage all around. Color: Royal Blue.