Hi Paula,
The 00200 safety cutter is not made to cut cardboard--This gadget is great for cutting through clamp shell packaging, coupons, envelopes, packaging, ect since it uses a micro ceramic blade. :)
If you are cutting cardboard boxes, which does require more blade depth, I would recommend using our 10503/10400 box cutters or any of our utility knives, 10550/10554/10558.
Thank you Paula! //TEAM SLICE//