I use this backing up thing with all my rulers. I position my rotary cutter blade about an 1/4th - 1/2 of an inch up from the bottom of the fabric, pull back towards me to the edge of the fabric and then zoom forward - right up the edge of the ruler. It keeps me from hitting and trying to trim off the very corner of the ruler.
BTW, I haven't had any trouble with my June Tailor slotted ruler. I love it.
Originally Posted by BellaBoo
Cut away from you body as regular. Put the cutter blade in the tear drop opening at the top of it, bring the cutter blade back to the very beginning of the slot and then cut as normal. Less then a 1/2" altogether. Like backing a car up before you go straight.