Developed by artist David Jon Kassam. It arrived yesterday and this is my first go with it, in time for a 2-hour demo grisaille underpainting for value. It's amazing really. (I was going to post about it after I used it with color, but because I was so enthusiastic I couldn't wait. It's usually set on a tripod (there's an arm available to attach it to the easel if one wants), and since it's vertical and next to the painting surface the light is exactly the same. And as you're mixing pigments alongside your work it makes matching values and colors a matter of a glance. Also speeds things up remarkably, since you work back and forth from palette to painting with little distance to cover. Seems like that wouldn't be a big deal, but it turns out to be significant. It also eases strain on neck, shoulders, and back, which has been an issue for me. I'll be surprised if it doesn't catch on.