Artist Steve Pittelkow is a "marbler." It might sound like a job that has something to do with stone cutting or fatty meats, but marbling is actually an ancient art form used to create stone-like patterns on paper or cloth. It dates back to the 15th century and the Turkish-Ottoman Empire, when it was known as "Ebru," meaning cloud art. Pittelkow is an expert in the craft, and our ideastream cameras caught up with him on a recent visit to the Morgan Conservatory in Cleveland.