Just a difference of opinion Mike
I have cut several of Gary's patterns with a standard blade.
When I first started scrolling, my mentor taught me to enter a piece of wood, pivot 180 degrees and come out the same line I entered in.
When I first started it wasn't pretty, but after a short time I found I could spin the wood around by using my fingertips.
Gary does prefer spiral blades and talks about them through out the book.
I would cut any of his patterns I have seen so far with either a straight or a spiral. The funny thing is my mentor hates spirals
It is a completely different cutting technique that's for sure.
I also find that many of Gary's patterns have fewer cuts than is the trend these days.
His tutorial in the beginning of the book is great.
It covers everything from selecting the right picture to choosing the right software. He also explains how to make patterns without software.
IMHO he is the Daddy of portraits.