From a Wall Street Journal story by Ngai Yeung headlined “An Inventor Finds a Life’s Work Perfecting the Writing Pen”:

King Charles III was caught in a viral moment last year, cursing a leaky pen while signing a guest book.

Many people focused on his temper. Leighton Davies-Smith focused on the pen. “There’s nothing more frustrating,” he said, sympathizing with the king. “You want it to be 100% reliable every time it touches the paper.”