A product walkthrough needed a narrator: not a person, a synthesised voice reading a script over the screen recording. Simple enough on paper.
We wanted four things from that voice at once, and it turned out you cannot fully satisfy all four together.
Scottish — because the product carries a real name behind it, and a bland mid-Atlantic voice reading it back would have been wrong from the first sentence.
Natural — not like a robot reading a list.
Local — free and offline, no per-render cloud bill, no dependency on someone else's server staying up.
