0.8mm and 1600 holes/strikes per cm is the target according to the experts who spent 15 years on this the follica thread has alot more detail on the front page
https://www.hairlosstalk.com/intera...croneedling-protocol-patent-disclosed.126994/
but thing i found interesting is the guy who this thread is about used a drpen / generic pen on fastest setting , slowest i ever seen for cheap pens is 12000rpm and 18000rpm fastest the derminator runs at 1500 rpm .
in his how to video he needles for about 12 minutes with alot of hair slowing him pausing but still if his pen is doing 18000 to do what he was doing equivalent with a derminator and same amount of pauses and hair combing etc it would take 2 hours 40 mins.
he seems to be massively over doing it but im sure that means were were under doing it so im hoping thats why it didnt work for us derminator users.