Following advice on a previous tread, I've ordered a bunch of ultra leather. I'm pretty experienced at sewing clothing, but not upholstery. I did a practice run with naugahyde making a dog cushion (box cushion, separate pieces for four sides, top and bottom . . . haven't done the zipper yet). It's different from cloth, like you can't use pins, the material doesn't readily lie down, and you can't easily coerce it iinto shape using a steam iron.
The guidelines I've found for ultra leather
say it's more like fabric than leather or vinyl, and recommend needles, threads, etc.
In most of the photos I've found, airstream cushions have been made using a pattern that I'd describe as a tube with zipper, with rectangular end inserts . . . as opposed to a box. Doesn't seem like top-stitching is popular.
I'd really appreciate links to technical descriptions of what what is done and why.... I may end out, for sake of economy,doing box cushions with vinyl on the bottom and ultra leather on top. I like top stitching, but find it's hard to do on a vinyl box. May be easier with ultra leather. Also worried that ultra is more stretchy than other vinyl, and that could end out with measurement problems and puckers. I guess you just use a lot of those clips that are used in place of pins to avoid the problem. Yes?
The ultra leather is so damn expensive I want to get it right the first time.