Excerpt from my article on the ancient Greek painter Apelles for TheCollector.

According to an ancient anecdote, Apelles once visited the house of Protogenes but did not find him there. Before leaving, he decided to leave a message to alert the host of his presence. He found a large panel, took a brush, and drew one of the fine colored lines, for which he was known. Later in the day Protogenes returned home and saw the line. Immediately, he recognized the elegance and precision of Apelles’s hand. “This is a direct challenge”, he must have thought before taking his brush. In response, he drew a line even finer and more precise on top of the previous one. Sometime later, Apelles returned and put an end to the competition. He drew a line within the previous two that was nearly invisible.

No man could possibly surpass this. Apelles had won.