I put a brand new blade in my Olfa knife, measured everything 3 times, and sheared one of my outboard spar webs. It turned out perfectly. I went painfully slow with the knife, making sure not to slip out of the scoring groove I was cutting. Made about 30 passes along the straightedge - I know, seems a little excessive, but I wanted the edge to break very cleanly because I'm going to use the next piece as the other web. No problem there. I stopped after cutting one because I was getting a little tired, and I didn't want to get sloppy. I'll do the other tomorrow morning.