Logan Graphic Products Graphic 3-Step Oval & Circle Cutter

I don't know if it will cut 8-ply mats - I have my doubts! I only use my cutter on 4-ply mats, it does an excellent job. When I firmly seat the standard cutting blade all the way down into the holder and use it to cut ovals and circles, it scores the backing sheet (4-ply) without cutting all the way through. You might try and contact Logan Graphic Products for their answer to your question.