Now, I don't have the time to go to the library or interview an artist, but I am an artist myself, so I think I can do this question. Painting can take anywhere from 2 hours to 2 months. It depends on how inspired you are, how much experience you've had, and how much you like what you are doing. Vincent van Gogh was very inspired by his surroundings and had been painting for 25 years at that time, so it's no surprise that he was able to make so many paintings in such a short time span.