I tried a sketchbook first, and my box cutter really struggled with the trimming part. My cover ended up looking chewed! So I left this one un-trimmed, though it was close enough that I'm happy with it. I'll try again when I get a new box cutter blade! Overall though, this was very simple and a fun way to repurpose old spiral bound school notebooks into something i'll actually use! I added a few additional holes to help the binding feel a little more secure.