This "Gypsy" yarn is a single ply yarn containing thread, fabric, wool, alpaca, glitz and so much more! Lush collected fibers and whatnots from lots of different Etsy sellers. And you can also buy crazy novelty batts or roving, with lots of different bits already mixed together you can spin from.
Novelty yarn is typically better for small, fun projects like neckwarmers, hats, clutches, or maybe even some mittens! Usually you can get enough of the same novelty yarn to do something like, a sweater, but you could collected different skeins of art yarn and make a crazy awesome sweater!