My medicine cabinet design includes an ebonized shelf. Ebony itself is far too expensive for this (and nearly any other project), and I did not want to use something like marble or a synthetic substance. I chose to continue to use white oak, but looked for a way to change the color of the wood.
I looked around for a few suggestions, and considered an ebony wood stain and a Tandy Leather black dye. Then I watched a segment of The Woodsmith Shop where they used an india ink to ebonize the feet of a small box. Sounded like a winner to me so I went looking for it here in Omaha.
There are huge price differences in what this product is sold for in local stores. I ended up taking back the 2 oz bottle that I bought at one place and bought 8 oz for slightly more from Dick Blick art supplies. I questioned whether 2 oz might be enough for both projects, so I am happy to have the larger bottle at a much better price.
I will say one thing about using india ink. It got on things that I did not intend. I noticed days later little spots were on other pieces of wood that happened to by lying around when I created samples. Fortunately for me, I noticed that before I started on the real stuff, and cleared everything else away. Make sure you wear a glove, and protect your clothing. This stuff does not come out.
Because the product is water based, I was able to apply two coats in a short amount of time and it was nice and dry later in the day. I sprayed it with lacquer the next day to seal it, and I will apply a couple more coats before I glue this piece into the cabinet.
You can see from the picture that the wood still shows its oak grain, which I like.
If you are looking for a way to ebonize a portion of your project, I would suggest looking at india ink. This particular brand is called Black Cat.