wrenkins, it's a great visual but that's bad. It has to be a problem with the manufacturing. Actually, I have attached iron-on interfacing to a knit - very carefully. So, I have technically ironed some. If the cut pieces roll, you could try double sided washaway tape to hold them together when you sew. I've made a set of dance costumes with a striped knit with the structural integrity of wet tissue. If I looked at it, it shifted out of alignment. I had to lay it out crosswise because if the stripes were horizontal, they looked like a patch-eyed drunken pirate had cut it out on a ship in a hurricane.