Thomas Paine, written on a whiteboard with two round-point markers banded together. As you can see, it’s not easy to write straight at this size (x-height approx. 15 centimetres or 6 inches) without the help of guidelines!
When doing calligraphy workshops I usually project guidelines (on a PowerPoint slide) onto the board using a projector, taking care to ensure that the slide is quite dark (e.g. grey) so it doesn’t dazzle the audience. This was written as I was winding down after an English grammar class that ended late in the day.