I used painters tape to adhere the pieces. This is still tacky enough to keep the paper and fusible web with paper sides up. However, you still need to be careful taking it off, it can rip the pattern.
Of course, I turned my back this morning and I have a visitor. The monarch has emerged. The other two cocoons are about to hatch as well. Once they start moving around I'll get a better photo. For now, I don't want to disturb them while it is drying it's wings. I hope I can catch one of them emerging from the cocoon.