Parker rust-proofing process.
A 1925 trade publication issued by the Parker Rust-Proof Company, the firm that promoted its phosphate rust-proofing process for metal parts, and aimed at manufacturers and finishers. The pictures show metal components and fittings before and after treatment, including steel rods, brackets, a wire-mesh basket rack and a sheet-metal fender, photographed plainly against light grounds. A designer could take from them the matte grey finish and the look of treated industrial steel for surface texture references.
