Challenge 305Sharp knives result in better cuts. Frequent sharpening helps your cutter knives perform at their best. As a rule of thumb, your cutter knife needs to be sharpened around every 2,000 to 5,000 cuts. Here are a few telltale signs that it's time to sharpen your knives:

 

• The knife hesitates or stalls while making a cut.

• The sheets are not all cut to the same length (usually the top few sheets are longer than the rest of the sheets - this is sometimes called "draw")

• Cut marks appear on the paper's cut face.

• The profile of the cut (side view) is not perpendicular to the table.

• The cut does not appear straight when viewed from the top.

• The knife makes a "rougher" sound as it passes through paper.

• Nicks are visible on the cutting edge of the knife.