Latex foam, which comes from rubber tree sap, features durable spring-back to hold its shape for 20+ years—much longer than traditional poly foam that you'll typically find in a sofa. Our wool fiber-filled back pillows maintain lasting fullness and structure, too. Naturally pliant, wool fibers can bend an astonishing 20,000 times before they break! Overall, both of these natural materials offer more resilience, structure, and support than standard poly foams and fillings—all while being easier on the planet and better to bring into your home.