It may be one of 2 or 3 different types. The best (in my opinion) iron on material covering is Super Coverite. If that's what you want, get it quick from Tower Hobbies/Great Planes. They're doing a close out sale right now.

Get the Big rolls, and get a couple. The stuff will last on the shelf forever. I had a roll that took me 10 years to use up after I first opened the roll. The last foot was as good as the first.