Hot cups are also biodegradable and compostable, lined with NatureWorks Ingeo polylactic acid (PLA). The white colored paper is Elemental Chlorine Free (ECF) which means they are bleached without elemental chlorine. Most cups you'll find on the market are lined with polyethylene and wont compost. These are compostable and heat resistant up to 200 degrees Fahrenheit.Cafes, restaurants and cafeterias require paper products for their look, printability and general customer acceptance. Technologically, it's very hard to make something similar to paper cups from alternative fibers. Still researching to see if paper cups and bowls can be made from a mix of alternative fibers, recycled fibers and responsibly managed wood/paper fibers to create a more sustainable product.