How do you know when a painting is 'finished'? Mmm, that's a difficult one. Sometimes you think it's finished but after afew days of living with it and staring at it and thinking about it, you think more can be done and so you do a few more little tweeks. Then you might try hanging it in a different room, with different lighting. This can often come as a bit of a shock, as you realise it looks completely different to how you thought it looked when working on it all that time.