Tubes are a Paint Shop Pro tool that is basicaly scaleable clipart -- a single image, or multiple images that you "paint" with, on a transparent background. They aren't like brushes, you can't change colour or transparency of the tube itself without using layers, the shape and image remain the same regardless of size, and with little to no "talent" needed. You can create a tube of say, the Mona Lisa. Suddenly, you have HUNDREDS of her all over your page with a stroke of the mouse. That's precisely the problem. Some people take pieces of an artist's copyrighted work, cut them out, put them on the transparent background, and use someone else's work to make their own.