From the manufacturer:

What makes our filters different?

• We use 100% natural unbleached paper. Our filters aren't white, because neither are trees.
• They are 100% compostable and biodegradable. When you're finished, return them to the Earth with the tea inside. The result is nutrient rich soil, not landfill.
• We use only wood pulp from trees harvested in North America. The trees removed aren't decimating rainforests. The pulp comes from growers who use sustainably harvested wood. For every tree they cut, they plant two.
• Our filters are manufactured in Canada and provide jobs to Americans and Canadians in the process. While our tea is grown worldwide, we're still dedicated to providing jobs at home whenever possible.
• Even our packaging is friendly. Our tea filters are packaged in lightweight recycled cardboard. It's convenient, sustainable, and uses minimal fossil fuel for transportation.