David, sorry for not responding earlier. I had Chicago Canvas & Supply make me a seamless 20x15 white canvas. It costs a lot more going seamless at that size. I think it was around $800, maybe with shipping. This was custom made for me. Here's their link: https://www.chicagocanvas.com/
@dacooper I needed a wide drop and for my session I turned a seamless 107” paper on iits side and could go for miles. Having a smooth wall to secure it to helps. I used canvas for the flooring but you could use the same paper for flooring to get a seamless look.
David, sorry for not responding earlier. I had Chicago Canvas & Supply make me a seamless 20x15 white canvas. It costs a lot more going seamless at that size. I think it was around $800, maybe with shipping. This was custom made for me. Here's their link: https://www.chicagocanvas.com/
Hope that helps!
Ron