Sleeve Padding Material?

So since I'm having trouble deciding on what bag I want, and I don't need it right now anyway because as long as I have a good sleeve, I can just put it in my current bag and wait till closer before college I buy a nice new bag. Well, today I ended up coming into possesion of this really pretty fabric and I was looking at it and I thought: hey, this would make an awesome sleeve for my new notebook! It's coming Tuesday, so this would be a nice project for me.

The thing is fabric alone obviously fails at padding. And I have no idea what kind of material to use to make a good padding for a laptop sleeve. Anyone have any suggestions? Household/easy to buy things would be best. Worst case scenario I can go totally bootleg and use a thick towel or something, but I'd prefer now to if there was a better option. So yeah. Yall know what would make good padding to protect me laptop from harm?

 

polyurethane foam. something like this?

http://www.uline.com/Browse_Listing_865.asp?desc=Soft+Foam

 

just get an egg crate (mattress pad) from target, bed bath and beyond, etc. Should be cheap and would probably be a good kind of foam for it.

 

mmm, good idea. The poly foam alone seems to be hard to obtain and expensive cause they wanna force me to buy in bulk. Plus I'd like to get it this weekend so online ordering won't do.