1940. Cennini says: When you have put in a year, you may sometimes just draw on paper with a pen. And if you want your drawings to come out a little more seductive, put some little washes on them, with a blunt minever brush. Do you realize what will happen to you if you practice drawing with a pen? -It will make you expert, skilful, and capable of much drawing out of our own head.
1941. The point is that the skillful artist draws with the pen, a tool that allows of no correction. And the novice draws with the pencil because it can be erased, and the beginner draws with a pencil in one hand and an eraser in the other always ready to scratch out their uncertain and hesitant lines. So when Vasari says Giotto draws his circle with the pen, it is no absentminded observation.
1942. But now my explanation becomes very difficult and complicated and I have to beg you to try and follow what I am going to say. It is the most obscure observation, and yet one of the most important. Vasari says, “fixing his arm firmly against his side to make a compass of it, with a turn of his hand he made a circle so perfect that it was a marvel to see it.” What does this sentence mean?
1943. Consider for a moment how the parts of the body can produce a circle. All of the body’s joints function as a sort of pivot, producing various portions of a circle in their movements. So, the digit of the finger can produce a quarter circle, and the hand by itself will produce most of a half circle. The arm, if placed with the elbow on a table can be used as a compass to draw a half circle...