So you have sharpened your folding knife to perfection and want to try it out by cutting some cardboard. You head downstairs to that pile of shipping boxes you’ve been meaning to break down and grin as you pull out your folder. A push cut should just be a breeze, you think, and proceed to cut. But the knife hesitates and an unexpected push is required to slice down through the first piece. What’s going on, you wonder.
It could very well be your technique. Cardboard is stiff and depending on its orientation it acts like a beam and resists moving out of the way as the blade wedges through. Try this: tilt your knife away from the natural 90 degree orientation to the face of the material, say 45 degrees. Then as you cut, the cardboard has a place to move and won’t jam the blade.