Made a YouTube video of the best way to rough up Plastic Canvas.
I have done this now over a dozen times and it works awesome. Thanks to Srusso for explaining it to me.
Use the Darice brand #7 Mesh material. There are 2 different types of this product available, the normal kind and one marked "extra stiff". The normal kind roughs up quicker but tends to rip a little easier if you rough it up to much, and it gets a little flimsy. I prefer to use the Extra Stiff material, it takes a little longer to rough up, but once it's rough it still retains the shape and stiffness.
Use a saw blade with really sharp pointy teeth. Time for a Monty Python quote. "Death awaits you all, with nasty sharp pointy teeth!"