This is an 18in x 24in cutting mat with self healing 5-layer construction. Reversible design with a dark background on one side and a light background on the other. Easy to use layout with 2 sets of corresponding numbers for reading left to right or right to left. No more counting backwards! Accurate 1in grid with 1/8in marks for precise alignment as well as 30 degree, 45 degree, 60 degree, and 90 degree guide lines to help the cutting process.