Interesting - I'd never heard of Smart-Fab! I just Googled it and I keep seeing it described as "disposable fabric" - I wonder why they call it that? Maybe Kraft-Tex is heavier? It is pretty thick stuff. Smart-Fab sure is a lot cheaper and comes in a lot more colors.
See what you've done? Now I have to buy some of THAT to experiment with, too! LOL
I do some paper crafting and book binding too, so these products fascinate me for a whole list of reasons.