We source high-grade plywood to be used for the top [land] layer of your map. Our current options are a stunning red Mahogany and a European Birch with a spicy grain. For the ocean layers we use MDF wood that is painted using thoughtfully graduated shades of acrylic paint. To connect each layer of wood we use PVA glue. We intentionally chose this because it creates a very strong bond, dries clear, and is non-toxic and completely biodegradable! Lastly, we use a food-grade timber oil to protect the top plywood layer, and bring out the natural grain.