Waxed & lined cardboard
Because of their chemical coating, waxed cardboard can take up to 50 years to break down in a landfill. The “wax” that you can scrape off is actually polyethylene, a plastic that keeps the cardboard inside from getting soggy, perfect for produce and coffee cups.
Waxy cardboard is mainly used for things like produce boxes that are delivered to places like grocery stores and restaurants. It’s worth nothing that waxy cardboard is often confused with glossy cardboard or paper – glossy material can and should be recycled, and in most cases you can put glossy material out with your regular cardboard and paper curbside recycling.