My first canvas

My first package of canvas just arrived from B&H, and I was surprised to find it not lying flat in the box; it was just kind of... flopped around on these air pillows. Now I have to admit this is going to sound stupid, because it is canvas, after all, and canvas is fabric, which is usually floppy, but still, I was surprised to find a package of ... floppy... canvas sheets. How can they pass through the printer (Pro9000MkII) with no rigidity to them? Do I need to do something to flatten them out first?

Take a look at this.
http://www.breathingco​lor.com …ets-in-a-desktop-printer/

Thanks Dan. I'd read something vague about that leader strip so it's nice to see something straightforward.