Shou sugi ban
This process originated in Japan in the 18th century as way to treat wood to make it weatherproof. The process involves charring the wood surface to render it a deep charcoal black. Next the top layer of char is removed with wire brush to open the pores. Lots of variations can occur here depending on the final look you want to achieve. Typically, after the top layer is removed I hand rub boiled linseed oil on to further protect and pull the grain and char out of the wood.
The resulting texture and color is amazing.