We manufacture in rust resistant stainless steel but like stainless steel knives rust marks can appear if products are not cared for correctly. It is very important to ensure stainless steel is dried throughly after use and you take care not to use abrasive detergents or cloths. By gently rubbing with a non abrasive cloth and baking soda solution you shoud be able to remove these marks. If your product has a coating you should not do this as it can lead to damage.