One hour is what I usually allow myself to paint a 6"x 6" painting. I thought that particular still life would be easy to paint. A simple flower, the cup that I painted many times before and a simple vase. It wasn't that simple after all. I spent way too much time on the flower. I just couldn't get the temperature of purple in the shadows and lights. Not only values need to be right, also temperature to get the likeness. I tried very hard to see but couldn't, so I used my logic. The source light was warm, so the lights needed to have some yellow in them. I added yellow, still something wasn't right. After an hour of struggling I wiped the flower completely off and started over. It usually helps. My favorite part in this painting is the palette knife - just a couple of strokes and it looked convincing.