Replacement for clay/balsa

Does anybody remember the substitute material for balsa wood? It was in FSM about a year or two ago where one of the featured modeler used this lightweight material that had similar characteristics of Balsa wood. I can’t remember what he was scratchbuilding or even what issue of FSM it was. I was wondering if anybody has used it or similar material and what their opinions on it was. I also would not mind know where I can order some and how much it is. That boths me that I cannot remember. I usually have good recolection on that stuff.

Hey Snoopy is this what your thinking about?

http://www.dickblick.com/zz331/11a/products.asp?param=0&ig_id=30

Could you be referring to basswood?

Woody,
You hit the spot. That is exactly what I was looking for. Thanks for your help.

Quincy,
No it was the Balsa Foam. Bass wood is hard than Balsa. The Balsa foam is suppose to be very light and easy to carve. I am going to check out the price now to see if it is cost effective on first time scratchbuilders like me. Thanks for getting back to me though. Appreciate it!!!