Wool retains heat, so it’s like projects get ironed from both sides at the same time, all while saving energy. Made of premium quality New Zealand wool that is tightly felted and absorbs moisture from heat allowing for minimal to no required steaming. .50" thickness keeps fabric stable and minimizes stretching. Projects can be pinned to mat for blocking. Soft smooth surface and lightweight and portable. Use of steam not recommended when ironing. Do not use on top of a cutting mat. Do not roll or fold mat.