Typically 9H to 10H. Typically 7H to 9H. It involves using a set of pencils with varying hardness levels (from soft 6B to hard 9H and even 10H) to scratch the coated surface. Supermaxx ceramic coatings claim to achieve 9H hardness for their baseline coatings and 10H hardness for their 2K Hybrid/Graphene variants when multi-layered.
