Ratio designed their Flat Bottom Paper Filters to extract the full potential from your ground coffee. Made with laboratory-grade paper that is 100% virgin wood pulp, these filters boast consistent and precise flow-through. Their bottom width measures 3.5in, their top edge a 2.25in height and 5.75in width. Reviewers are quick to note that the paper doesn’t carry a flavor, which may mean you can skip the pre-wetting stage (though make sure to test that yourself beforehand if your preferences are different!).
