I used a knife similar to your Osborne for years cutting leather. I now have a round knife and wonder why I didn't get one a long time ago. Pretty tough to beat a round knife for cutting out leather IMO. Watch Tandy's round knife how to video. That's what sold me on one... http://www.tandyleatherfactory.com/en-usd/Use-and-Care-of-the-Round-Knife.aspx