Dritz-omnigrid mat.Omnigrid mats have several unique features that quilters appreciate: one side features a medium green background with bright yellow grid lines and the other side features a solid grey without grid lines.Both sides feature a forgiving surface and will not damage your rotary cutter.The grids on these mats feature inch markings to the 1/8 inch and a full surface grid with 45 degree angles as well.Mat measures 18.75×12.75 inches with an 12×18 inch grid.