Here's what I got from the Rotatrim product manager. Hope this is helpful...
Looks like they had the same lessons in Euclidian geometry I had way back but did not completely understand it. Mr. Gouweloos, my old teacher sitting next to Euclidius up there in heaven and looking down with only one eye open should get the credit for what I write here.
I cut one corner less so get at 3x the fault one step earlier than they get. They make a mistake that one can get 4x the fault represented. There are 4 90 degr angles in a square or rectangle, the sum is 360 degr, if I cut 3x 91 degr then the one left is 87 degr, an extra corner cut gives the same result just shifts the 87 degr angle to the next corner, a fifth cut gives the same result. In short the accumulation can not be more than 3x as the sheet has just 4 corners.
When you get near a 18 degr fault repeating it becomes a 4x accumulation but then they had seen a pentagon sheet on that cutter :-)
Send this message back to them and let them send me a coupon for the "brain" work done. Mr Gouweloos can not cash anymore but he was a superb teacher in every aspect.
Met vriendelijke groet, Ernsthttp://www.pigment-print.com/spectralplots/spectrumviz_1.htm
December 2012, 500+ inkjet media white spectral plots.