In “The Material Ratio Curve” we look at this rather well-known curve (historically known as the Abbott-Firestone Curve). It shows us the amount of material that we encounter as we move further down into a surface. That can tell us a lot about the surface: how durable it may be, how it could carry lubrication, how well it may wear…even how comfortable it may be to slide around on (not recommended!).

In this introduction we show how the material ratio curve is derived. Then, we show you some examples that will help you estimate the nature of a surface from the shape of its material ratio curve.