In the block with strips, you can have three strips of equal width, or you can have the middle one wider, so long as the block equals in size the other block. For example, if you are using 6.5" unfinished blocks, you could use 2.5 + 2.5+ 2.5, or you could use 2 + 3.5 + 2. I usually like the middle strip to be wider, but that's just my preference...