Does chemicaly blueing or blackening help resist rust?

[Hengelo_77]

I have some 1.2519 toolsteel here.
It is not stainless, but on the good hand I believe it lets itself be blued or blackened.
Does that help make it more resistant to rusting?

Mirror polishing helps steel resist rust, are there more ways?

 

[Stacy E. Apelt - Bladesmith]

When you blue or blacken a carbon steel blade, you put an oxide layer on the surface. That prevents the Iron under the layer from rusting. It isn't bulletproof, but it greatly resists rust.
Stacy

 

[mete]

It also holds a bit of oil which helps too.But as any gun owner knows you still have to take good care and see that the steel is coated always with a light layer of oil.A coating like 'Parkerizing' [zinc or manganese phosphate] used on military gune in the past held even more oil and was quite durable.

 

[Original]

EEZOX synthetic gun lube and rust preventitive works excellent and is a dry film. The Best I have ever used.

 

[John R. Fraps]

or if you get all the treating done, add a coat, or more, of Renassiance Wax (spelling). It is good stuff

 

[Hengelo_77]

OK, I understand, thnx.
Besides colour are there differences between blueing and blackening?
Does the gritt size the knife gets finished up to make any difference on the result?

I am thinking of firstly mirrorpolishing the knife for rust-resistance and then either blueing or blackening it for extra protection.