The standard material thickness of our Steel planters is 2mm. "Patina" is a natural fixed coating of rust that provides protection against further corrosion. Surface characteristic of Steel is a brown rust orange colour and natural patina marks. When exposed to the open air, the steel is covered with this protective rust layer. This natural solid rust layer forms the protection against further corrosion of the underlying steel. Steel is a weatherproof steel and is a metal alloy, consisting of iron to which copper, silicon, nickel and chromium have been added. This product will arrive to you unweathered in an exposed metal finish and will naturally need to gain it's patina once you have placed it into location. This can take between 3 months - 12 months all depending on the weather conditions, the time of year, moisture changes etc. All water bowls have 1 x drainage hole in the middle. If you order a water bowl, there will be a plug included to close the hole. If you order a fire bowl, there will be no plug included. Very strong and wear-resistant Weatherproof and durable material Made in Europe. If for any reason the patina marking is not to your liking or it has patina unevenly, you are able to lightly sand the surface to remove the patina, this will start the patina process again.