A thick marker makes detail impossible, and that’s the point. When you sketch with something that can’t draw a fine line, you’re forced to stay at the level of structure and flow. [[Breadboarding over wireframes]] works from the same principle: low fidelity isn’t a limitation, it’s protection against premature attachment to a specific solution. The roughness signals to everyone in the room that nothing here is final.
The constraint is a communication tool as much as a process tool. A rough sketch says this is for thinking, not approval, in a way a polished wireframe doesn’t. [[Save screenshots]] of these rough sketches before moving on: the logic captured in an imprecise sketch is often more useful later than the refined version that followed it.