Obsidian 3M, I’ve also used ceramic it. Plotter mainly, I use a handle squeegee with an Orange Crush bit. I start from the top where a 3rd brake light would be and go straight down as low as my hand will allow and then go right from the middle of the glass and take it all down from there. I do the same on the left side of the split I made and then user a slammer tool to secure the bottom and that’s where the fingers will some times come back. For the bottom I use the slammer starting from the middle and work my way to the side In both directions.