Craft Edge

I'm using my 12x24 cutting mat for the first time today. And cutting a normal piece of vinyl. When cutting the vinyl on a 12x12 cutting mat, I use a pressure of 6 and a speed of 8 and have great results. While using the 12x24, it is not cutting all the way through the vinyl. Even with pressure at 9 and speed at 4. It's leaving a microscopic layer of vinyl untouched, making weeding the vinyl very difficult. I have noticed that the 24" mat is slightly thinner than the 12" mat, which I'm assuming is the issue. Is there any way to adjust my cutter for this thickness issue?

I'm a newbi here so here's a thought, not a tried solution. If you think the mat problem is because it's too thin, why not get a sheet of poster board/thin card stock(about the thickness of the vinyl or so) and tape it to the back of the cutting mat, same size as cutting mat to make it a bit thicker. Run a test or two
Wyndham

The extra length on a 24" mat can also cause bowing in the middle and inconsistent cuts. Try placing a stack of books, magazines, cardstock (whatever), in the front and back of the cutter to make sure the extra long mat is supported horizontally. It can make a big difference.