1936. “Now,” said the Duck, “buried in this story are a great many things that have to be pointed out, and I would have had no idea at all about them, not being an artists myself, but a friend of mine whose job it was to do the restorations of the murals of the Library I was once studying in was good enough one day to point out the many subtleties of this story to me. I do not remember the artists name, but I remember very well what he had to say about Giotto’s O.”
1937. “First,” he said, “we note that Vasari is specific about what Giotto used to make his circle. He drew his circle with a pen and he used red paint. Why did he use red paint, you ask? He used red because that was the color mixed up on his work table when the request was made, in short, Giotto has stopped what he is doing for a moment to accommodate the Pope’s agent.”
1938. You may think this is unimportant but you would be wrong, because it is integral to the purpose of the story, Giotto is aware of the importance of his work, and does not interrupt what he is doing more than necessary to accommodate the Pope’s request. More than that, the courier in the story is put off and almost insulted by the apparently offhand manor of Giotto, and thinks he has to deal with a fool.
1939. Next consider that Giotto does not draw his circle with a pencil. This is obvious enough, because the pencil did not exist at that time, but instead he might have used a silverpoint, or leaden style, the Renaissance predecessor of the pencil. Why did Giotto use a pen, rather than the pencil? To answer that question we have to go back from Vasari two hundred years and consider the writings of Cennini who explains for us the difference between drawing with a pencil and drawing with a pen.