Some of my UVU illustration friends and I had quite a heated discussion on art thievery. We found another artist trying to pass off other people's work as his own and we were all pretty incensed about it. There's quite a big difference between using reference to maintain accuracy and using other people's actual painted artwork in your own piece. I make no mention of giving credit. Because it just shouldn't be done.
Paint your own work.
Have artistic integrity.
Be nice and play fair.
I mention all this because for our recent assignment in Richard's class, we were to take an abstract word and create a concrete image for it. My assigned word was: Power.
I used a lot of reference for this piece. There's no way I could paint a realistic light bulb without looking at a light bulb reference. I don't have the muscles memorized (like a lot of artists I know), so I can't just paint an accurate figure with bulging muscles. But I painted it all by hand, like I was painting on a canvas (except your paintings on canvas don't just arbitrarily disappear at random times) and while it's not perfect, I'm pretty proud of it. I've come a long way since the first speed painting in Digital Painting for Illustration 1!