Our Aluminum Balusters are treated with powder-coating. Powder-coating is a dry finishing process in which finely ground particles of pigment and resin are electrostatically charged and sprayed onto an electrically grounded post cap. The charged powder particles adhere to the grounded post cap until they melt and fuse into a smooth coating in the curing oven. The result is a uniform, durable, high-quality finish that is also environmentally friendly. Our Classic, Baroque, Arc, Estate and Traditional balusters are powder-coated with AAMA2604 compliant material, which provides 5 times the outdoor exposure and twice the humidity exposure as AAMA2603.