QS Ruler 9x 12 MatSelf healing, multi layer mat that is usable on both sides, with a light background on one side & a dark background on the other One inch line with two sets of corresponding numbers are placed around the perimeter of the mat and read left to right & right to left never lose your place or have to count backwards! This versatile mat was created with function & simplicity in mind with 1 8", 1 4", 1 2", 3 4", & 1" markings as well as multiple angles Tips