We use a @johnwilsonblades5180 Pattern 99 Revolution blade to show the difference between a new blade, and one that needs replacing. New blades will have a “sharpening line” for you to gauge how much “life” is left in the blade. If you are unsure how much life the blades started with, you can check the original sharpening life based on the bottom toe pick. Stainless Steel blade like Eclipse, Step, Gam and other, will have a etched line on one side of the blade as they are not chromed like a carbon steel blade.