Hi Robert,

Thanks for your interest. The tiles are textured before they are glazed, but the amber glaze fills in the texture and creates lighter and darker values where the glaze is correspondingly thicker or thinner. If you run your fingers across the finished tile, you can feel traces of the underlying texture, but they are relatively smooth and easy to clean. It's an old process, made popular by American art tile companies around the turn of the 20th century, such as Sherwin and Cotton called Emaux Ombrants.