Geri B

...in addition to all of the above......as you are cutting, your spread fingers on that ruler should be parallel to your rotary cutter...so you place your spider-leg like fingers down with good pressure onto the ruler, cut just pasted your fingers, stop, but leaving rotary cutter in fabric,reposition your fingers to uncut area and continue cut.....takes longer to write this and sounds more convoluted than it is, but doing it is smooth and pretty much foolproof....becomes automatic over time...