Carbon steel is one of the most often used steels in the custom knifemaking world. this steel can reach a very high hardness while still being quite easy to work. So you end up with a auper sharp edge that is still easy to sharpen.
This type of steel does not contain any chromium, or any other corrosion resistant element. The iron in this steel is therefore free to oxydise with the oxygene in water and in the air.
However this isn't a bad thing. This capacity to oxydise also allows the steel to create a fine layer of patina that will actually protect it.
Consequently, a minimum of maintenance is needed for carbon steel. Simply wipe the blade completely dry between tasks in the kitchen, never leaving food on the steel and after cleaning it.
With every carbon steel blade we make, a small bottle of mineral oil is provided to be applied after cleaning and drying the blade. This oil is also perfect for conditionning the handle for time to time.
The stainless steel we most often use contains chromium which prevents the iron from reacting with oxygen. This alloy is therefore much easier to maintain. Be careful though, stainless steel does not mean dishwasher safe!
Stainless steel is also much harder to work. Whether on the anvil or the grinder or even in the kitchen, it's an abrasion resistant material. For the knifemaker, this changes a lot of things. For the knife user, this means it only takes a little bit longer to sharpen. These are the reasons why a handmade stainless knife will often go for a higher price. More work, more time, more sand paper.