I mean you've kinda already got the answer to your question right there in your post.... :)

But, I recently did my first inlay too (see the last page of my build thread for a picture) and was getting some lovely 0.5mm wide lines. I used a carbide 30 degree V bit 1/8th inch shank 0.1mm tip from shop-apt. Couldn't be happier with this supplier, was recommended them on here, but they're probably not the cheapest.

https://www.shop-apt.co.uk/carbide-e...-round-30.html
https://www.shop-apt.co.uk/high-perf...its-20-90.html