I'm looking to match the butt style casing installation of my old home. Standard 45 mitered casing and planning the backside has worked for me in newer homes
I've never seen trim installed like this, but it intrigues me.
Hopefully you can provide me some insight.
I edited my original question as I originally did not know the name of this cut. So my answer would be how to correctly measure and cut jack miters for window and door casing. Specifically how to cut a 45 degree angle through just the decorative part