What's good for padding?

[red-xera.livejournal.com]

I've barely had my laptop for over two weeks and because of my stupidity it already has scratches on the top from the adapter plug. So to hide the scratches from my mom and to prevent any future damage, I've decided to make a laptop cover. How I'm planning it in my mind is that I want to fill the inside of the cover with some sort of padding so it can have extra protection but I don't know what sort of padding to use. I'm going to be bringing this with me to school and back on the TTC in my messenger bag so it's going to be taking some hard knocks. Not intentionally of course but these sort of things happen.