10' x 10' is huge, I would first suggest trying something a little smaller, especially since 10' is taller than an average interior wall, which is typically around 8' tall. Being able to paint that entire surface as a speed painting would be very difficult, though I'm sure it is not impossible. I just know I would definitely not be able to reach the top and would have a hard time going back and forth so much. If you are set on that size, you will probably have to custom order materials. There are probably companies that have banner type materials in the size you need, but industry standard is typically 8' at the widest, and is then on a roll. I am sure that large format printers would have at least up to 12' wide though. You may be able to search for large format printing in your area or look online to see what you can find. You may have to call to custom order the blank material and have it shipped. You may be able to find an actual canvas to use, but it will not be affordable, plus if it does not come primed you will need to prime it since speed painting relies on the paint going on fairly smoothly which would not happen on an unprimed canvas. Typical banner material would be smooth enough already but may be too smooth and the paint may not stick as well and you may get a lot of extra dripping. Getting something 10' x 10' is just not something that you will likely be able to easily find locally. Again, I would suggest a little smaller. I have worked on a 4' x 4' canvas, which is easier to find or make, and that was a great size. It was big enough to make an impact yet small enough to be somewhat manageable. That one was stretched so transporting it was a little difficult because even 4' x 4' does not fit into a regular vehicle. We had to carefully lean it in a pickup bed. The 10' x 10' would likely need to be loose. You could probably figure out a way to tie it up to do the painting but would need it to be able to fold or roll to get it transported anywhere for the most part. I hope this answer was helpful and that you are able to figure something out that will work for you. Good luck on your painting, I would love to see how it turned out and what worked!