
Now, there is what Giorgio Vasari writes in his book Lives of the Artists- volume1. There is an episode between Paolo Ucello and Donatello.
The story goes- that Ucello was once commissioned to paint over the door of the church on San Tomasso in the Old Market a fresco showing St Thomas feeling for a wound in Christ’s side, and that he put all he could into the work. saying that he wanted to display all his ability and knowledge. So he had a screen of planks put up round the painting to keep it hidden until it was ready. One day Donatello met him on his own and said: “And what kind of work is this that you’ve hidden behind a screen?”
Paolo answered: “You just have to wait and see.”
Donatello would not press him any further, expecting that he would see some miracle, as usual, when the time came. Then one morning Donatello happened to be buying some fruit in the Old Market when he saw that Ucello was uncovering his work. He greeted Paolo courteously, and Paolo, who was anxious to have his opinion, asked him what he thought of the painting. After he had closely scrutinized it, Donatello commented:
“Well now, Paolo, now that it ought to be covered up, you’re showing it to the whole world.”
Paolo was deeply offended by this, and finding that instead of the praise he had anticipated he was being censured for this, his last work, he felt so humiliated that he no longer had the heart to go of doors, and he shut himself up in his house and devoted all his time to perspective, which kept him poor and secluded till the day he died- 1475, he was buried in the church of Santo Spirito.