I've read photographers write about using a cyclo wall instead of a seamless background. What is a cyclo wall?
In a large professional studio (think of something that you'd bring a vehicle into to photograph) a cyclo wall is a permanent installation that serves the same purpose as a seamless background paper setup. A cove, or curved transition, is built between wall and floor (usually a bendable plywood over a rib form), and the wall, cove and floor are painted the same color, usually white. The wall stops short of the ceiling so lights can be fired from above and behind. Think of a light table (not a transparency viewer -- one of those deals with a plexi sweep) writ large. The idea, as with seamless paper, is to allow the subject to appear to float in space, often to allow the subject image to be "keyed out" later for print, although it is just as easy to create a gradient background with lighting alone. It is used mostly for large product photography (vehicles and major appliances), although something at a somewhat smaller scale would be useful for fashion (particularly catalog) shoots.
A 'cyclo wall,' also referred to in various combinations of 'infinity,' 'seamless,' 'cyc,' 'cyclo,' 'wall,' 'drop,' 'backdrop,' and 'background,' are all synonyms for the same thing:
A backdrop which curves smoothly at the floor in order to eliminate the 'corner' where the wall meets the floor, thereby providing the illusion that the floor stretches on to infinity.
Visual top-down example of a 'cyclo wall:'
In short, a seamless background and a cyclo wall are different terms for the same thing.