All of our mounted canvases are attached to 1/4" masonite. Masonite is the strongest and best option for strength and durability. Masonite will resist the shrinking and stretching that happens naturally with canvas.
Although we can cater to specific requests, we recommend staying away from other materials, especially foam core. Canvas will shrink after it's attached to the foam board, and the foam board will warp. Even if the foam is held in place by a frame, the foam board will eventually warp and start to look "wavy."
We attach the canvas to the masonite with a heat press. There is a layer of adhesive film placed between the canvas and the masonite, which makes the mount permanent and protects the canvas from any harmful substances that might be on/in the masonite.
The heat press provides enough heat to activate the adhesive film and then attaches the canvas with thousands of pounds of pressure. This assures a permanent bond.
After the canvas cools we apply multiple layers of lacquer. The lacquer protects the other side of your canvas and provides levels of contrast and saturation. You'll be shocked at just how faithful and vibrant the colors are.
We don't believe there are better materials anywhere. While some online shops provide a variety of other options (I.e. Printing on glass, aluminum, etc.), none of them have durability and longevity that the Masonite/canvas combo provides.