Is this it?
http://www.overrainbow.com/cgi-bin/S...cking5=froogle?
So to make each line of v's longer, just keep going. If it wants, say, 30 fabric pieces, make it go to 40 (or however long to get the length you want).
Then just add an extra few v's to get the width you want. With guesstimation math, I think you would need 3 extra v's. Or a wide border, or a few borders, if you're only using jellyrolls
Hope that helps