"I have been in many art classes and have even instructed some. I am in a class now I have some concerns about. The main concern is the teacher painting on the student's canvas, then the student signs her name as though she is the artist. Some of the work is hers but much is not. My question is about the legality of entering such a painting in a contest or even just a show. I personally think a teacher should demonstrate, even paint (to show) on a panel board or something extra. Am I wrong?" -- LV
Some teachers never hesitate to work on a students' painting, others will only ever demonstrate in a corner or on a separate piece of paper. Certainly I think a teacher should ask before working on the actual painting, and not take offense if someone says no.
If someone does work on a painting, I wouldn't claim it as one of mine alone, and I would make a note on it along the lines of "with the assistance of XYZ" to remind myself. When I'm in a workshop I don't usually mind the tutor working on my actual piece, because often it's the fastest way of showing me what needs doing. But I also don't hesitate to say "okay, stop, I get it". Sometimes I'll ask a tutor to show me what they mean, and then I generally expect them to work on my painting or drawing.
Many competitions and shows exclude paintings done in a workshop/class in their rules, precisely because the degree of tutor input is unknown. As for legality, I'm not a lawyer so I can't give an answer on that. In my opinion though, I guess it depends on how much was done, and how much of it is still visible. For me it would have to be minimal.
Inevitably it'll turn out that some tutors just don't suit you, and it sounds like this is one of them. I'd either accept your losses and leave, or grit your teeth and get from the class what you can while it runs. Don't let it put you off art classes or workshops. You always learn something, though it's not always what you expect.
