Cardboard boxes often have a clay material mixed in which makes them dull blades fast. Your small blade on the spartan should do more than cut paper with a sawing motion. I can cut paper that way with very dull knives. The small blade on my climber can cut paper with a swipe. No sawing motion needed. If you have the 1,000 grit fine rods for the lansky, use them. You should never spend more than 30 minutes on a knife. Use more pressure with course grit to get the blade to your rough shape. Use moderate pressure on the finer grit to bring the edge were you want it.