Chipboard or Posterboard

I have made a couple of shape books now and the previous shape books were made with brown chipboard that I got from the inserts that are in the boxes that reams of paper comes in. This is the chipboard. It is already sized at 8 1/2 by 11 inches.
I am not quite happy at the results using this kind of chipboard. The edges show sort of a grey shade, which to me looks like an "unfinished" piece of work.

The current book that I am working on, I wanted to try something different. So I bought several packs of this white posterboard at Wal-Mart. It comes in a pack of 5 pre-cut sheets of 11x14 in size. I wasn't sure if this would hold up sturdy enough or not, but decided to give it a try.

The posterboard cut out very nice with the Cricut machine with no problems at all. I then used DCWV cardstock for my layers to attach to the front and back of the posterboard. This cardstock helped make the posterboard thicker. And it is just as sturdy as using the brown chipboard I had used previously. I am now convinced this is the type of material I will use for my shape/word books and was impressed at how "clean" the edges looked.

I definitely would recommend using this posterboard for these projects.