Good low cost way to get a black finish on A380 die cast aluminum

I work for a power tool manufacturer. We are developing a new tool to replace an existing product. The ID for the new product requires the main housing to be black. We have painted housings in the past but it is rather expensive and requires masking.
I am wondering what other alternatives are out there to achieve a nice looking black finish on a die cast aluminum part. The casting alloy is A380.
Currently we also texture the outside of our housings with stainless steel shot blasting to hide any blemishes that may arise from heat check in the die. Ideally any finishing process should be able to still look nice even with our shot blast finish.
Any information would be helpful.
Thanks,

If heat treatment is not problem you can oil you objects very sparingly(with peanut, soy or any other edible oil or fat),then heat it slowly to 400 °C. Instead oil you can use 2o shellac solution(Bake it when lacquer is dry).

Good luck!