I'm a newbie when it comes to working with leather, so any input would be greatly appreciated. I wanted to start making some gear for my dog like leads, collars, and harnessesetc. and decided to make a leash first. I have a few leads that I have taken apart, so I know how the braiding is done, The question I have is what is the best way to make the slits? I was using a utility knife, but they are coming out crooked and don't look very professional. The leather I'm using is 5/8" wide so it's hard to use the straight edge and knife at the same time.
This is the type of leash I'm looking to produce.