I don't use a backer because if you forget and apply to much pressure, snap, no more worries because it is useless now. I use electrical tape as a guide for my cut as well as to keep any vibration down that may cause problems while cutting, I also do the cutting freehand. Cut a little dip it in room temp water, cold water has a better chance of warping the razor. A little at a time and slowly, you should do fine.