1) He did jobs no body else wanted do
2) He helped people escape
I've found that three of the most important techniques are "Oil, Fresco, and Tempera" and if you take a look of the paintings you can actually see that they are really I could say creamy, realistic, colorful, like "hard worked", you can truly see every brush-stroke and they also depict beauty of the human body.
And, on the other hand we have the "new techniques" where you find works that are also realistic but not as creamy and hard worked as the old, in that type of works you can also see that there's not a lot of work with brush-strokes like in the old ones.
