Will a brushed nickel or matte black finish resist rust in a humid bathroom?

The stainless-steel (SUS304) holders here are marketed as rustproof, and verified-purchase ratings are broadly positive on finish durability. Spot-resist brushed nickel finishes, like Moen's, are also frequently praised for hiding water spots. That said, because we found no independent lab corrosion testing for this category, treat rustproof claims as manufacturer marketing corroborated only by customer impressions over time.