In a store silly!! I have not figured out how to make it yet myself???
I am getting stuff called Seaboard, it is much much cheaper then Starboard and it the same thing!! Comes in more colors also!!
I bought the full 3/4 sheet last fall for $170, and I just bought a full sheet of 3/8 for $116 (54" X 96")
The $170 might be more now?? The web site has prices but they are not the same now. I told the guy he needs to update the site to reflect the increase.
The site says $86 for 3/8 but was $116 when I got there.
So I have no idea what a 3/4 would go for right now?
But it is still Much cheaper Starboard!!
Here they are :
http://www.jfreeman.com/cpg_seaboard.html