So it looks like it depends on what material and thickness you need. LMII has an info table giving total circumference of a few popular body sizes. It says a Dreadnaught is about 61” around. Some of the binding axiom sells is up to 60” which is enough to use one piece around the top, but it looks as if almost all options for celluloid will need a second piece for the back.
I contacted John Hall of blues creek guitars, and he told me to look to Amazon. I bought a piece of Musicilly(sp?) Chinese made Tortoise binding that was about 64” long. Who knows if it’s celluloid, it did soften with acetone, but not like other material i have, and is pretty light colored, but is for sure long!
On a separate note, how do you builder approach side purfling? Do you buy it pre-laminated to your binding, or are you laminating it and then bending it in house? I’d like to be able to pull off side binding, but can’t seem to get my purfling to do what I want without breaking.