Some hammocks have wooden supports that go across the width of the hammock. These supports keep it laying flat. Other hammocks lack the wooden support, but this saves space, and is a good option for convenience. Hammocks also come in many materials and colors. Rope is a common material chosen for backyard hammocks. Rope is a good material to prevent leaves and debris from collecting in the hammock. Cloth is another common material for hammocks, providing a durable surface for relaxation. Colors are available to match any outdoor decor.