Powder coating involves spraying charged dry powder onto a (usually pre-galvanised) steel surface and curing it in an oven at 160–200 °C, which melts and crosslinks the powder into a tough, abrasion-resistant film 60–120 μm thick. It produces deeper, more uniform colour than wet paint and resists chipping and UV better.
For outdoor metalwork in Australia, the standard duplex system is hot-dip galvanise + powder-coat: the galvanising provides corrosion resistance, the powder coat provides the chosen colour and a sacrificial top layer. Common colours are Dulux 'Monument', 'Surfmist', 'Basalt', 'Woodland Grey'.
CAD60 title blocks can record the finish system (e.g. 'HDG + Dulux Monument') so the workshop and the powder-coater work from the same spec.