Dritz Dura-Heal Cutting Mats are designed for use with rotary cutters and craft knives, the rotary cutter marks seem to disappear into the mat. Mat has an extra border that extends past the gridded area for easy measuring and cutting. Precise 1 inch grid markings and bias lines are helpful when aligning your fabric and ruler accurate cutting. One side of the mat has grid markings, and the other side is plain, and either side of the mat can be used for cutting. 18in x 24in.