My favourite rulers are the O'Lipfa lipe edge rulers. I love that little extra edge that hangs onto my cutting board and makes it far more secure so it does not slip when cutting. For added assurance I also add the little clear plastic ruler grippers. The sand paper ones don't work that well for me. I just wish O'Lipfa made their rulers in all sizes. They do have a 5"X24" (my personal favourite) a 3"X18" and a 4"X36' which is great for wider fabrics. The lines are black and easy to see. If you can try out a few of your friend's rulers first, it might help you decide. Not every ruler will be equally loved by all quilters.