Flintknapping techniques - spalling, percussion, pressure flaking, and notching - to make an obsidian blade. By learning some of these methods, you can craft a stone tool that'll make you feel confident in your abilities to make a sharp edge in a survival situation. Let's break them down: Spalling involves striking the obsidian to remove large flakes in order to begin creating a rough blade shape. Next, percussion flaking refines the edge by tapping off smaller flakes with a bopper or hammerston