Metal Etching
Quite often, necessity is the mother of learning a new technique or skill.
When I was designing the work One Map, One Path I had taken a digital OS map of an area of the Scottish highlands and used this to create a digital file that I wanted an engineering company to use to cut out the design into the stainless steel discs. Unfortunately, I couldn't find anyone who had the capability to do this. I then thought about photo-etching or laser-engraving the design, but this was going to be prohibitively expensive.
As a last resort, I read about electrolytic-etching and made my own etching system.
Although not perfect, I managed to etch all the discs.