Hi -they are black from use, not marked up. Photopolymer stamps are prone to staining, especially with darker colors like red and black. However, any color can stain the stamps to some degree. To reduce staining, stamp them with a pale color, like Pink Pirouette, before using them with darker colors. This will offer some resistance to staining and help keep the stamps looking good. But as you can see, when used lots like the heart/wings!
