A marbling tray must be usable and durable to work. There are two size trays - A3 and A4 for marbling. Three different types of marbling trays are made of steel, galvanize or plastic. You can find all three kinds of marbling trays with different colors and different sizes on Karin Art (karinsanat.com) online market. Karin marbling trays are very durable and can be used for years. You can leave the water you swamped in the tray in safe which is made by Karin Marbling.