Coffins are tapered at the shoulder while caskets are completely rectangular. It doesn’t matter which you use, it is just a matter of preference. Here are more facts about caskets: Coffins and caskets are non-biodegradable. In Australia, 85 to 90 percent of coffins are solid wood and particle board, but in the U.S. only about 10 to 15 percent are made of wood and particle board with hardwood veneers. Most of the coffins in the U.S., or about 80 to 85 percent, are made out of stamped steel.
Traditional caskets in the United Kingdom are made of chipboard covered in a thin veneer. The issue is that apart from not decomposing, caskets and coffins can be toxic from the finish and glue that hold them together and they contaminate the ground.
Caskets and coffins are often manufactured using exotic and even endangered species of wood. They’re designed to prevent decomposition. Most burial sites encourage environmentally friendly coffins and caskets made of cardboard or wicker.