Porcelain vs. painted steel vs. glass — which whiteboard surface lasts longest?

Across the reviewers we read, porcelain-on-steel is the consensus pick for ghost-free, scratch-resistant writing surfaces, with manufacturers and retailers describing it as the standard for classrooms and conference rooms. Glass boards (tempered) also resist ghosting well and look more modern, but specialist-community threads warn about shipping breakage and weak magnet hold. Painted-steel and melamine boards are far cheaper but verified-purchase reviewers note ghosting after months of heavy use.