Not only has pre-painted steel been treated for corrosion-resistance, the process saves time for manufacturers by painting the steel at the factory and maintaining a temperature-controlled facility.
These are typically exterior surfaces ready for end-use applications and buildings. Pre-painted steel saves a step for manufacturers, so they can easily complete a steel roof or produce garage doors. Different types of paint can be applied depending on your needs in gloss or weather-resistance. Typically, a silicone paint will perform better when exposed to sun and rain than a polyester paint, but both serve different end goals.